Anyone here flicker sensitive?

>
>
> Hi Svetaswan,
>
> Your symptoms sound like typical symptoms of new LED lit screens, rather
> than the tradition fluorescent tube (CCFL) lighting of LCD screens.
>
> I have enormous difficulty looking at my new Acer laptop LED lit screen, as
> does my partner. I have never had any problem with normal CCFL LCD screens.
> I have always had problems with low refresh rate CRT monitors - 60-80Hz
> would cause some strain, above 85Hz generally fine, BUT this LED strain is
> different altogether.
>
> Like many, it took me some while to realise it was the screen itself
> causing
> the problem (rather than emfs or wifi etc. concerns)- I went online and was
> surprise at how many others were experiencing the same thing, from strain
> through disorientation and even nausea.
>
> There's no obvious explanation as to why it happens, some say not dimming
> helps, as dimming is achieved by lowering the LED refresh rate, some say
> blinking helps and my partner finds sunglasses at full screen brightness
> makes it bearable!
>
> But for me, none of those help and I can only bear a few minutes before
> severe symptoms start kicking in (general weird brain-strain, eyestrain,
> fatigue, disorientation).
>
> The GOOD news is that by simply connecting my 'normal' CCFL monitor to my
> Acer laptop, I can merrily work for hours with no problem (WiFi IS off,
> mind
> you, as confirmed by my electrosmog detector).
>
> It looks like LED screens are becoming a BIG issue (unless they can solve
> this problem)
>
> Good luck
>
> John
>
> PS here is a page where macbook owners share their Experiences with the new
> LED screens; I can relate to just about every post here, and recommend
> reading them all:
>
> http://discussions.info.apple.com/thread.jspa?threadID=1677617
> <
> http://discussions.info.apple.com/thread.jspa?threadID=1677617&start=45&tst
> art=0> &start=45&tstart=0
>
> I can also attest to having severe eye strain from LED displays.
>
> I have spent countless long days staring at many types of monitors (CRT,
> LCD, Plasma) with no problems. Then, in January, I purchased a new Macbook
> Pro with an LED display only to realize that after about an hour I would
> get
> headaches and my eyes felt severely strained.
>
> I have used a combination of full spectrum desk lighting and frequent
> breaks, but I still cannot work on my computer all day like I used to. I
> didn't fully understand that it was LED technology causing the eye problems
> until my Dad purchased a new LED television recently, and I immediately
> experienced the same eye strain within a half-hour of watching his
> television.
>
> That experience led to more research and this thread, which confirms that
> at
> least some others are experiencing issues with this display type.
>
> My advice to others is try out LED displays before purchasing because
> sensitivity can occur even if you've never had eye strain before. My only
> solution now is to either sell my Macbook Pro or buy an additional monitor,
> which will at least help with home work.
>
> This is a problem whether it's blinding the masses or not. I am glad that
> other people have reported a problem because I thought I was losing my
> mind.
> Don't know what I'm going to do because it's taken me more than two weeks
> to
> get to the bottom of this problem. I love Apple, but I also hate them. You
> get a few choice and live and die by those choices. I waited on the
> non-glare screen, but still the LED seems to be causing me a problem.
> Grrrr.
> I feel trapped.
>
> I get sore eyes, But i thought this was just because i had glasses, and to
> speak, I never had this problem with my iBook. The way i found to fix it is
> to 1. Turn the Brightness Down, 2. Blink More (You have to think about this
> when you are concentrating).
>
> Add me to the list of people strongly affected by this issue.
>
> I've been using computers since the Apple ][ days and typically spend hours
> per day in front of screen displays. I have never experienced anything like
> the nausea and headaches I've been feeling since I purchased the new
> Macbook
> Pro.
>
> It ranges from "unpleasant" to "completely debilitating". None of my other
> laptops or monitors have caused this problem before.
>
> Like many of you, I'm reluctant to give up what is an otherwise nice
> machine
> (and I'm out of my 14-day return window), but this is not something I can
> live with.
>
> If anyone has found anything that works for them, please share. I'm going
> to
> do some experiments over the next few days with brightness settings, but I
> am not optimistic at this point.
>
> Well, I had to give up the MacBook Pro. I'm working on one of the last
> MacBooks with an LCD screen. I got it yesterday. You see, Apple just
> announced that even MacBooks are now coming out with LED Backlit screens.I
> feel fortunate that I figured this out before the LCD screen became
> extinct.
> Yes, I miss my MBPro, but in a few days I'll adjust to the slightly slower
> speed and the smaller screen. My eyes definitely feel better. I visited my
> eye doctor yesterday before I made the decision and took my computer. She
> said that she noticed my eyes tearing up from the strain of the looking at
> the screen in just a few minutes. This is a real phenomenon and I hope
> Apple
> will make note and provide the LCD screen as an option.
>
> Having the non-glare screen on the LED seems to make no difference IF you
> are sensitive to the light generated by the LED technology. I had had my
> MBPro for about six weeks. It took time to identify what was causing the
> problem. I visited two Apple stores, taking material from the Internet, and
> managers at both places said they had "heard" something about this issue
> and
> would have no problem trading out the machine, in spite of the time.
>
> I waited until I saw my doctor, hoping she could prescribe some special
> glasses, but no. I returned to one of the stores and hoped to get a hard
> drive larger than the 160, but I would have to get that online. The store
> manager said I could do the exchange online with no problem. NOT TRUE. I
> went to my car and phoned Apple and was told that I was outside of the
> 14-day window, there was no swapping, and was there anything else I needed
> help with. I didn't see the point in mentioning the letter I had from the
> doctor or anything since I was right outside of a store and could get the
> computer that day, rather than wait, after begging. The manager of the
> store
> could not have been nicer. I was impressed.
>
> So, yes, I miss the MBP, but I've rationalized: My old iBook had 60 GB, so
> 160 is more than twice that. I had a 12" screen before, now I have 13". So,
> I didn't get to go state-of-the-art with the MBP, but my eyes aren't on
> fire.
>
> This is a real problem that a few, very light sensitive people have.
> Blinking and dimming the screen did not help. Deselecting the ambient light
> option did not help. There were certain lighting conditions where it didn't
> hurt as much, but that was a moving target trying to combine time of day,
> position of window blinds, and position of desk---hard to hit with a
> searing
> headache.
>
> Another option is to keep the MBP and get an external monitor. MBP works
> closed, a specialist told me, and you can sit the monitor on top of it. Get
> the magic and avoid the burn that way.
>
> hey i bought my laptop from mac about a month ago
> and since then my vision has become very shaky
> and becoming worse and worse everyday
> when i drive when i try to focus on cars infront of me
> or to the left or right of me they seem to dissapear
> for a second then reappear and sometimes
> they seem to be doing a shutter movement
> day or night its the same thing
> i just got my eyes checked out to make sure it wasnt that
> the doctor said my eyes are perfectly fine
> i was doing some research yesterday
> and found all of you out there with the same problems
> im trying to return my macbook pro and they arent being coorperative
> i cant drive anymore because of how bad my vision has gotten
> and it doesnt seem like anyone at apple cares what so ever
>
> purchased the new LED monitor for my MacBook Air and it works great.
>
> However I have experienced severe headaches and feelings of nausea up to
> dissorientation. I am totaly confident that this is the monitor as my
> girlfriend and I were doing some work together on my monitor last night and
> she expereinced severe reaction with nausea and dizzyness. After 30 minutes
> away from the monitor she was fine. I have experienced this from the first
> day I got he monitor and it does this in any light conditions in the room,
> no matter how far I sit from it or light level settings.
>
> I dont want to give up the monitor but I feel sick every time I use it. The
> previous monitor I was using was the LCD version of the same monitor and it
> gave me no problem whatsoever.
>
> Apple - please address this - it is very real and people are feeling like
> they are getting the flu or sick.
>
> Wow, I truly appreciate this post and all the people who have wrote back.I
> just bought the new 21.5 Imac and without realizing the screen difference
> between my March 2009 20"Imac and the new Nov 2009 21.5" Imac, I started to
> get a tense burning in my eyes the first few days of using it. I had never
> felt this before with the March 2009 20 inch Imac with the LCD screen that
> I
> had used for almost 1 year. I am now going to return the new one.
>
> I want someone to tell me that there is a fix because the new machine is a
> bit faster and of course it is "newer". However, there is none and the
> trade
> off does not compare. I thought I may be over reacting, but now as I am
> using the old one again the screen looks much softer and not so sharp and
> my
> eyes are not hurting me any longer. Nothing more to be said!
>
> I also was wondering if I was going blind or something.
>
> I used to have ccfl macbook pro but it got stolen.
>
> After reading text on my recently purchased used macbook pro my eyes would
> shift out of focus and I felt like I was tripping on something for a few
> seconds. Then it goes away. And then it would happen again. Obviously some
> kind of sync or refresh issue. This doesn't happen to me viewing anything
> else.
>
> Yeah so it almost makes the laptop useless for reading text.
>
> One thing that helps is speed reading. If I read almost too fast it doesn't
> happen as much. But if I leisurely read it will go all unfocused.
>
> I have a feeling newer versions have better technology and do not do it as
> much. Oh there it goes I'm going all cross eyed again or whatever. This is
> frustrating!
>
> I bought my macbook just when it came out in October 2008. It has the
> led-backlit glossy screen. I have noticed that over the past year, my
> eyesight has worsened and that seeing long-distance is especially worse off
> than before. I have also gotten intense headaches, something that I have
> never experienced before purchasing the macbook.
> I think that my usage of the macbook, that is, looking at the computer
> screen for several hours a day for the past year has affected my eyesight.
> Permanently? I'm not sure. If I'm able to change my screen to matte, and I
> have noticed that I can see normal then I will post back on this forum
> again.
>
> have an imac and have experienced what I guess is eye strain ever since
> getting it. Eye feels like it is pulling or my face can literally
> ache....dry eyes....gee, it has sure changed my computer experience. I have
> been to the eye dr. and he found no changes in my eyes. So I have just been
> winging it and hoping to hear something similar to help me with my problem.
> I am lowering the brightness, changing to white on black background when I
> can, wearing sunglasses....eyedrops.....geez.....it almost seems like APPLE
> should have a complaint page about this issue. Not sure about this changing
> the gamma setting?? Any more input is greatly appreciated!
>
> Anyway, what I wanted to share is the fact that the chopper circuit that
> controls the LED backlight dimming is operating at a far higher frequency
> than have been previous versions of LED backlit panels in Apple's
> notebooks.
> In fact, it looks to my eyes to be an order of magnitude higher, which
> would
> mean higher than 3 kilohertz switching. This is really good news. The
> frequency is so high that normal phosphor decay dominates the operating
> characteristic of the white LEDs in dimming mode, and not the switching
> frequency as was the case before. That puts LED backlit LCDs much more on
> par with previous generation CCFL backlit LCDs, and perhaps even better
> than, at least with respect to this particular type of flicker.
>
> If people really were suffering ill effects from the lower blinking
> frequency of the LEDs before, then the new ones should start reducing the
> number of complaints about eyestrain, headaches, dizziness, nausea, etc.
> that have been seen on these discussion forums. Time will tell. But I'm
> really encouraged by this development. Someone is listening somewhere.
>
> For all of you doubters out there. I replaced my LED screen for a non-LED
> screen and the eye strain headaches were gone instantly. 100% gone!
> No doubt about it.
>
> cont... I just want to emphasize that I traded in my LED glossy screen for
> a non-LED glossy screen. My eye strain headaches were gone instantly and I
> have never seen them since despite the fact that I am still using a glossy
> screen.
>
> Oh, and by the way, I went to the eye doctor recently and my eyes are
> approximately the same as they have always been.
>
> There is no doubt that LED was giving me a miserable headache. Perhaps it
> was me and not all users will have the same reaction. But, with that being
> said, I would urge all to take caution with the new LED screens.
>
> _____
>
> From: [hidden email] <eSens%40yahoogroups.com> [mailto:
> [hidden email] <eSens%40yahoogroups.com>] On Behalf Of
> svetaswan
> Sent: 11 May 2010 05:40
> To: [hidden email] <eSens%40yahoogroups.com>
> Subject: [eSens] Anyone here flicker sensitive?
>
>
> Hi all,
>
> Twice, I've done Richard Conrad's flicker-sensitivity test - where I put a
> dark towel over my laptop's screen to test my response. Both times, I
> noticed a definite relief - a type of "destressing" of my brain (possibly
> my
> eyes, too). This certainly doesn't mean that "flicker sensitivity" is
> responsible for all of my "computer woes" - but apparently, it is part of
> the problem.
>
> Great - so whenever I'm in front of this screen, my brain is having little
> seizures. Life is good. ;-/
>
> Anyway, this realization led me to try to look up information on the screen
> that's attached to this laptop. Such information is quite hard to come by
> (Dell doesn't even seem to give any information about the screen in the
> User's manual or its official listing of specs) - but I managed to come
> across a site that listed this screen's refresh rate as being 60Hz, and its
> "response time" as being 25ms ("rise") to 35ms ("fall"). From what I know
> about LCD displays, a 25ms response time is quite a bad number - it seems
> that the absolute maxium response time for a LCD to be considered any good
> is 8ms.
>
> But my question is, how does response time contribute to flicker
> sensitivity? Does a "slow" response time contribute any to flicker/screen
> sensitivity, or is it all about refresh rate?
>
> Does response time factor into the equation when you're, say, reading
> webpages or watching YouTube? Could the slow response time be contributing
> to my screen sensitivity?
>
> Oh, and I also dim the screen - because of my sensitivity/intolerance to
> screen brightness. Could the dimming of the screen be contributing in some
> way to my brain's adverse response to this display? (Because of the
> "chopping" effect?)
>
> Considering my apparent flicker sensitivity, should I look for a LCD witha
> 85Hz or greater refresh rate, or would it be sufficient if I just found one
> with a low (say, 5ms) response time? LCD monitors with low response times
> are relatively easy to come by these days - LCDs with a greater than 60Hz
> refresh rate are harder to come by (and more expensive).
>
> For those of you flicker sensitive, what has worked for you as far as LCD
> monitors go? Is finding a montior with 85Hz-or-greater refresh rate
> absolutely essential - or could you "cover" for a 60Hz refresh rate by
> getting a display with a relatively-low resolution, and/or a low
> response-time? What size screen, and other screen parameters, have worked
> for you?
>
> Any and all responses welcome (there may be some of you who are not flicker
> sensitive, but who may have knowledge on this topic). Thanks in advance,
>
> ~Svetaswan
>
> [Non-text portions of this message have been removed]
>
>  
>

>
>
> Hi Svetaswan,
>
> Your symptoms sound like typical symptoms of new LED lit screens, rather
> than the tradition fluorescent tube (CCFL) lighting of LCD screens.
>
> I have enormous difficulty looking at my new Acer laptop LED lit screen, as
> does my partner. I have never had any problem with normal CCFL LCD screens.
> I have always had problems with low refresh rate CRT monitors - 60-80Hz
> would cause some strain, above 85Hz generally fine, BUT this LED strain is
> different altogether.
>
> Like many, it took me some while to realise it was the screen itself
> causing
> the problem (rather than emfs or wifi etc. concerns)- I went online and was
> surprise at how many others were experiencing the same thing, from strain
> through disorientation and even nausea.
>
> There's no obvious explanation as to why it happens, some say not dimming
> helps, as dimming is achieved by lowering the LED refresh rate, some say
> blinking helps and my partner finds sunglasses at full screen brightness
> makes it bearable!
>
> But for me, none of those help and I can only bear a few minutes before
> severe symptoms start kicking in (general weird brain-strain, eyestrain,
> fatigue, disorientation).
>
> The GOOD news is that by simply connecting my 'normal' CCFL monitor to my
> Acer laptop, I can merrily work for hours with no problem (WiFi IS off,
> mind
> you, as confirmed by my electrosmog detector).
>
> It looks like LED screens are becoming a BIG issue (unless they can solve
> this problem)
>
> Good luck
>
> John
>
> PS here is a page where macbook owners share their Experiences with the new
> LED screens; I can relate to just about every post here, and recommend
> reading them all:
>
> http://discussions.info.apple.com/thread.jspa?threadID=1677617
> <
> http://discussions.info.apple.com/thread.jspa?threadID=1677617&start=45&tst
> art=0> &start=45&tstart=0
>
> I can also attest to having severe eye strain from LED displays.
>
> I have spent countless long days staring at many types of monitors (CRT,
> LCD, Plasma) with no problems. Then, in January, I purchased a new Macbook
> Pro with an LED display only to realize that after about an hour I would
> get
> headaches and my eyes felt severely strained.
>
> I have used a combination of full spectrum desk lighting and frequent
> breaks, but I still cannot work on my computer all day like I used to. I
> didn't fully understand that it was LED technology causing the eye problems
> until my Dad purchased a new LED television recently, and I immediately
> experienced the same eye strain within a half-hour of watching his
> television.
>
> That experience led to more research and this thread, which confirms that
> at
> least some others are experiencing issues with this display type.
>
> My advice to others is try out LED displays before purchasing because
> sensitivity can occur even if you've never had eye strain before. My only
> solution now is to either sell my Macbook Pro or buy an additional monitor,
> which will at least help with home work.
>
> This is a problem whether it's blinding the masses or not. I am glad that
> other people have reported a problem because I thought I was losing my
> mind.
> Don't know what I'm going to do because it's taken me more than two weeks
> to
> get to the bottom of this problem. I love Apple, but I also hate them. You
> get a few choice and live and die by those choices. I waited on the
> non-glare screen, but still the LED seems to be causing me a problem.
> Grrrr.
> I feel trapped.
>
> I get sore eyes, But i thought this was just because i had glasses, and to
> speak, I never had this problem with my iBook. The way i found to fix it is
> to 1. Turn the Brightness Down, 2. Blink More (You have to think about this
> when you are concentrating).
>
> Add me to the list of people strongly affected by this issue.
>
> I've been using computers since the Apple ][ days and typically spend hours
> per day in front of screen displays. I have never experienced anything like
> the nausea and headaches I've been feeling since I purchased the new
> Macbook
> Pro.
>
> It ranges from "unpleasant" to "completely debilitating". None of my other
> laptops or monitors have caused this problem before.
>
> Like many of you, I'm reluctant to give up what is an otherwise nice
> machine
> (and I'm out of my 14-day return window), but this is not something I can
> live with.
>
> If anyone has found anything that works for them, please share. I'm going
> to
> do some experiments over the next few days with brightness settings, but I
> am not optimistic at this point.
>
> Well, I had to give up the MacBook Pro. I'm working on one of the last
> MacBooks with an LCD screen. I got it yesterday. You see, Apple just
> announced that even MacBooks are now coming out with LED Backlit screens.I
> feel fortunate that I figured this out before the LCD screen became
> extinct.
> Yes, I miss my MBPro, but in a few days I'll adjust to the slightly slower
> speed and the smaller screen. My eyes definitely feel better. I visited my
> eye doctor yesterday before I made the decision and took my computer. She
> said that she noticed my eyes tearing up from the strain of the looking at
> the screen in just a few minutes. This is a real phenomenon and I hope
> Apple
> will make note and provide the LCD screen as an option.
>
> Having the non-glare screen on the LED seems to make no difference IF you
> are sensitive to the light generated by the LED technology. I had had my
> MBPro for about six weeks. It took time to identify what was causing the
> problem. I visited two Apple stores, taking material from the Internet, and
> managers at both places said they had "heard" something about this issue
> and
> would have no problem trading out the machine, in spite of the time.
>
> I waited until I saw my doctor, hoping she could prescribe some special
> glasses, but no. I returned to one of the stores and hoped to get a hard
> drive larger than the 160, but I would have to get that online. The store
> manager said I could do the exchange online with no problem. NOT TRUE. I
> went to my car and phoned Apple and was told that I was outside of the
> 14-day window, there was no swapping, and was there anything else I needed
> help with. I didn't see the point in mentioning the letter I had from the
> doctor or anything since I was right outside of a store and could get the
> computer that day, rather than wait, after begging. The manager of the
> store
> could not have been nicer. I was impressed.
>
> So, yes, I miss the MBP, but I've rationalized: My old iBook had 60 GB, so
> 160 is more than twice that. I had a 12" screen before, now I have 13". So,
> I didn't get to go state-of-the-art with the MBP, but my eyes aren't on
> fire.
>
> This is a real problem that a few, very light sensitive people have.
> Blinking and dimming the screen did not help. Deselecting the ambient light
> option did not help. There were certain lighting conditions where it didn't
> hurt as much, but that was a moving target trying to combine time of day,
> position of window blinds, and position of desk---hard to hit with a
> searing
> headache.
>
> Another option is to keep the MBP and get an external monitor. MBP works
> closed, a specialist told me, and you can sit the monitor on top of it. Get
> the magic and avoid the burn that way.
>
> hey i bought my laptop from mac about a month ago
> and since then my vision has become very shaky
> and becoming worse and worse everyday
> when i drive when i try to focus on cars infront of me
> or to the left or right of me they seem to dissapear
> for a second then reappear and sometimes
> they seem to be doing a shutter movement
> day or night its the same thing
> i just got my eyes checked out to make sure it wasnt that
> the doctor said my eyes are perfectly fine
> i was doing some research yesterday
> and found all of you out there with the same problems
> im trying to return my macbook pro and they arent being coorperative
> i cant drive anymore because of how bad my vision has gotten
> and it doesnt seem like anyone at apple cares what so ever
>
> purchased the new LED monitor for my MacBook Air and it works great.
>
> However I have experienced severe headaches and feelings of nausea up to
> dissorientation. I am totaly confident that this is the monitor as my
> girlfriend and I were doing some work together on my monitor last night and
> she expereinced severe reaction with nausea and dizzyness. After 30 minutes
> away from the monitor she was fine. I have experienced this from the first
> day I got he monitor and it does this in any light conditions in the room,
> no matter how far I sit from it or light level settings.
>
> I dont want to give up the monitor but I feel sick every time I use it. The
> previous monitor I was using was the LCD version of the same monitor and it
> gave me no problem whatsoever.
>
> Apple - please address this - it is very real and people are feeling like
> they are getting the flu or sick.
>
> Wow, I truly appreciate this post and all the people who have wrote back.I
> just bought the new 21.5 Imac and without realizing the screen difference
> between my March 2009 20"Imac and the new Nov 2009 21.5" Imac, I started to
> get a tense burning in my eyes the first few days of using it. I had never
> felt this before with the March 2009 20 inch Imac with the LCD screen that
> I
> had used for almost 1 year. I am now going to return the new one.
>
> I want someone to tell me that there is a fix because the new machine is a
> bit faster and of course it is "newer". However, there is none and the
> trade
> off does not compare. I thought I may be over reacting, but now as I am
> using the old one again the screen looks much softer and not so sharp and
> my
> eyes are not hurting me any longer. Nothing more to be said!
>
> I also was wondering if I was going blind or something.
>
> I used to have ccfl macbook pro but it got stolen.
>
> After reading text on my recently purchased used macbook pro my eyes would
> shift out of focus and I felt like I was tripping on something for a few
> seconds. Then it goes away. And then it would happen again. Obviously some
> kind of sync or refresh issue. This doesn't happen to me viewing anything
> else.
>
> Yeah so it almost makes the laptop useless for reading text.
>
> One thing that helps is speed reading. If I read almost too fast it doesn't
> happen as much. But if I leisurely read it will go all unfocused.
>
> I have a feeling newer versions have better technology and do not do it as
> much. Oh there it goes I'm going all cross eyed again or whatever. This is
> frustrating!
>
> I bought my macbook just when it came out in October 2008. It has the
> led-backlit glossy screen. I have noticed that over the past year, my
> eyesight has worsened and that seeing long-distance is especially worse off
> than before. I have also gotten intense headaches, something that I have
> never experienced before purchasing the macbook.
> I think that my usage of the macbook, that is, looking at the computer
> screen for several hours a day for the past year has affected my eyesight.
> Permanently? I'm not sure. If I'm able to change my screen to matte, and I
> have noticed that I can see normal then I will post back on this forum
> again.
>
> have an imac and have experienced what I guess is eye strain ever since
> getting it. Eye feels like it is pulling or my face can literally
> ache....dry eyes....gee, it has sure changed my computer experience. I have
> been to the eye dr. and he found no changes in my eyes. So I have just been
> winging it and hoping to hear something similar to help me with my problem.
> I am lowering the brightness, changing to white on black background when I
> can, wearing sunglasses....eyedrops.....geez.....it almost seems like APPLE
> should have a complaint page about this issue. Not sure about this changing
> the gamma setting?? Any more input is greatly appreciated!
>
> Anyway, what I wanted to share is the fact that the chopper circuit that
> controls the LED backlight dimming is operating at a far higher frequency
> than have been previous versions of LED backlit panels in Apple's
> notebooks.
> In fact, it looks to my eyes to be an order of magnitude higher, which
> would
> mean higher than 3 kilohertz switching. This is really good news. The
> frequency is so high that normal phosphor decay dominates the operating
> characteristic of the white LEDs in dimming mode, and not the switching
> frequency as was the case before. That puts LED backlit LCDs much more on
> par with previous generation CCFL backlit LCDs, and perhaps even better
> than, at least with respect to this particular type of flicker.
>
> If people really were suffering ill effects from the lower blinking
> frequency of the LEDs before, then the new ones should start reducing the
> number of complaints about eyestrain, headaches, dizziness, nausea, etc.
> that have been seen on these discussion forums. Time will tell. But I'm
> really encouraged by this development. Someone is listening somewhere.
>
> For all of you doubters out there. I replaced my LED screen for a non-LED
> screen and the eye strain headaches were gone instantly. 100% gone!
> No doubt about it.
>
> cont... I just want to emphasize that I traded in my LED glossy screen for
> a non-LED glossy screen. My eye strain headaches were gone instantly and I
> have never seen them since despite the fact that I am still using a glossy
> screen.
>
> Oh, and by the way, I went to the eye doctor recently and my eyes are
> approximately the same as they have always been.
>
> There is no doubt that LED was giving me a miserable headache. Perhaps it
> was me and not all users will have the same reaction. But, with that being
> said, I would urge all to take caution with the new LED screens.
>
> _____
>
> From: [hidden email] <eSens%40yahoogroups.com> [mailto:
> [hidden email] <eSens%40yahoogroups.com>] On Behalf Of
> svetaswan
> Sent: 11 May 2010 05:40
> To: [hidden email] <eSens%40yahoogroups.com>
> Subject: [eSens] Anyone here flicker sensitive?
>
>
> Hi all,
>
> Twice, I've done Richard Conrad's flicker-sensitivity test - where I put a
> dark towel over my laptop's screen to test my response. Both times, I
> noticed a definite relief - a type of "destressing" of my brain (possibly
> my
> eyes, too). This certainly doesn't mean that "flicker sensitivity" is
> responsible for all of my "computer woes" - but apparently, it is part of
> the problem.
>
> Great - so whenever I'm in front of this screen, my brain is having little
> seizures. Life is good. ;-/
>
> Anyway, this realization led me to try to look up information on the screen
> that's attached to this laptop. Such information is quite hard to come by
> (Dell doesn't even seem to give any information about the screen in the
> User's manual or its official listing of specs) - but I managed to come
> across a site that listed this screen's refresh rate as being 60Hz, and its
> "response time" as being 25ms ("rise") to 35ms ("fall"). From what I know
> about LCD displays, a 25ms response time is quite a bad number - it seems
> that the absolute maxium response time for a LCD to be considered any good
> is 8ms.
>
> But my question is, how does response time contribute to flicker
> sensitivity? Does a "slow" response time contribute any to flicker/screen
> sensitivity, or is it all about refresh rate?
>
> Does response time factor into the equation when you're, say, reading
> webpages or watching YouTube? Could the slow response time be contributing
> to my screen sensitivity?
>
> Oh, and I also dim the screen - because of my sensitivity/intolerance to
> screen brightness. Could the dimming of the screen be contributing in some
> way to my brain's adverse response to this display? (Because of the
> "chopping" effect?)
>
> Considering my apparent flicker sensitivity, should I look for a LCD witha
> 85Hz or greater refresh rate, or would it be sufficient if I just found one
> with a low (say, 5ms) response time? LCD monitors with low response times
> are relatively easy to come by these days - LCDs with a greater than 60Hz
> refresh rate are harder to come by (and more expensive).
>
> For those of you flicker sensitive, what has worked for you as far as LCD
> monitors go? Is finding a montior with 85Hz-or-greater refresh rate
> absolutely essential - or could you "cover" for a 60Hz refresh rate by
> getting a display with a relatively-low resolution, and/or a low
> response-time? What size screen, and other screen parameters, have worked
> for you?
>
> Any and all responses welcome (there may be some of you who are not flicker
> sensitive, but who may have knowledge on this topic). Thanks in advance,
>
> ~Svetaswan
>
> [Non-text portions of this message have been removed]
>
> 
>

> surprise at how many others were experiencing the same thing, from strain
> through disorientation and even nausea.
>
> There's no obvious explanation as to why it happens, some say not dimming
> helps, as dimming is achieved by lowering the LED refresh rate, some say
> blinking helps and my partner finds sunglasses at full screen brightness
> makes it bearable!
>
> But for me, none of those help and I can only bear a few minutes before
> severe symptoms start kicking in (general weird brain-strain, eyestrain,
> fatigue, disorientation).
>
> The GOOD news is that by simply connecting my 'normal' CCFL monitor to my
> Acer laptop, I can merrily work for hours with no problem (WiFi IS off,
> mind
> you, as confirmed by my electrosmog detector).
>
> It looks like LED screens are becoming a BIG issue (unless they can solve
> this problem)
>
> Good luck
>
> John
>
> PS here is a page where macbook owners share their Experiences with the

>
>
> Excellent idea - as soon as my notebook is out of 12 month warrantee I will
> see if I can power up its LED array with a battery DC source, I'm sure it
> won't use up much power, and could easily be lit with some NiMH AAs.
>
> I find plenty of strain at full brightness, and it actually improves with
> reduced brightness! And there's less strain when the room is well lit.
>
> It's quite a mystery why there's this effect - I'm extremely sensitive to
> flicker, especially when looking out of corner of my eye, and yet this LED
> screen looks rock solid!
>
> I have NO problems with battery powered LEDs that I'm aware of - I use them
> a lot (eg for reading at night)
>
> Cheers
> John
>
>
> -----Original Message-----
> From: [hidden email] <eSens%40yahoogroups.com> [mailto:
> [hidden email] <eSens%40yahoogroups.com>] On Behalf Of Bill
> Bruno
> Sent: 11 May 2010 17:32
> To: [hidden email] <eSens%40yahoogroups.com>
> Subject: Re: [eSens] Anyone here flicker sensitive?
>
> Great info. I was looking forward to an LED monitor... now I'll wait
> and see. LED's can be turned on and off essentially instantly, unlike
> any other kind of light. An LED run directly off DC should have no
> flicker, but to get the best performance the DC voltage is generally
> regulated with a switching regulator. There is no way the eye could
> consciously perceive such a frequency, but it's conceivable it creates
> correlations in nerve firing times that then has some negative effect.
>
> When the brightness isn't 100% there will be a chopping action, which
> is much more likely to cause problems. It's possible that some do this even
> when set to 100%. Also, some screens have separate adjustments for
> brightness and back-light.
>
> You might try getting an old monitor shield for CRT's (to block static
> electricity) and use that to make it less bright.
>
> It would be interesting to rewire so the LEDs are fed from a rechargeable
> battery, or a linear power supply....
>
> On Tue, May 11, 2010 at 1:50 AM, John Jamieson
> <[hidden email] <john%40theomegashift.com>>wrote:
>
> >
> >
> > Hi Svetaswan,
> >
> > Your symptoms sound like typical symptoms of new LED lit screens, rather
> > than the tradition fluorescent tube (CCFL) lighting of LCD screens.
> >
> > I have enormous difficulty looking at my new Acer laptop LED lit screen,
> as
> > does my partner. I have never had any problem with normal CCFL LCD
> screens.
> > I have always had problems with low refresh rate CRT monitors - 60-80Hz
> > would cause some strain, above 85Hz generally fine, BUT this LED strain
> is
> > different altogether.
> >
> > Like many, it took me some while to realise it was the screen itself
> > causing
> > the problem (rather than emfs or wifi etc. concerns)- I went online and
> was
> > surprise at how many others were experiencing the same thing, from strain
> > through disorientation and even nausea.
> >
> > There's no obvious explanation as to why it happens, some say not dimming
> > helps, as dimming is achieved by lowering the LED refresh rate, some say
> > blinking helps and my partner finds sunglasses at full screen brightness
> > makes it bearable!
> >
> > But for me, none of those help and I can only bear a few minutes before
> > severe symptoms start kicking in (general weird brain-strain, eyestrain,
> > fatigue, disorientation).
> >
> > The GOOD news is that by simply connecting my 'normal' CCFL monitor to my
> > Acer laptop, I can merrily work for hours with no problem (WiFi IS off,
> > mind
> > you, as confirmed by my electrosmog detector).
> >
> > It looks like LED screens are becoming a BIG issue (unless they can solve
> > this problem)
> >
> > Good luck
> >
> > John
> >
> > PS here is a page where macbook owners share their Experiences with the
> new
> > LED screens; I can relate to just about every post here, and recommend
> > reading them all:
> >
> > http://discussions.info.apple.com/thread.jspa?threadID=1677617
> > <
> >
> http://discussions.info.apple.com/thread.jspa?threadID=1677617&start=45&tst
> > art=0> &start=45&tstart=0
> >
>
>  
>

>
> Hi Svetaswan,
>
>  
>
> Your symptoms sound like typical symptoms of new LED lit screens, rather
> than the tradition fluorescent tube (CCFL) lighting of LCD screens.
>
>  
>
> I have enormous difficulty looking at my new Acer laptop LED lit screen, as
> does my partner. I have never had any problem with normal CCFL LCD screens.
> I have always had problems with low refresh rate CRT monitors - 60-80Hz
> would cause some strain, above 85Hz generally fine, BUT this LED strain is
> different altogether.
>
>  
>
> Like many, it took me some while to realise it was the screen itself causing
> the problem (rather than emfs or wifi etc. concerns)- I went online and was
> surprise at how many others were experiencing the same thing, from strain
> through disorientation and even nausea.
>
>  
>
> There's no obvious explanation as to why it happens, some say not dimming
> helps, as dimming is achieved by lowering the LED refresh rate, some say
> blinking helps and my partner finds sunglasses at full screen brightness
> makes it bearable!
>
>  
>
> But for me, none of those help and I can only bear a few minutes before
> severe symptoms start kicking in (general weird brain-strain, eyestrain,
> fatigue, disorientation).
>
>  
>
> The GOOD news is that by simply connecting my 'normal' CCFL monitor to my
> Acer laptop, I can merrily work for hours with no problem (WiFi IS off, mind
> you, as confirmed by my electrosmog detector).
>
>  
>
> It looks like LED screens are becoming a BIG issue (unless they can solve
> this problem)
>
>  
>
> Good luck
>
> John
>
> PS here is a page where macbook owners share their Experiences with the new
> LED screens; I can relate to just about every post here, and recommend
> reading them all:
>
> http://discussions.info.apple.com/thread.jspa?threadID=1677617
> <http://discussions.info.apple.com/thread.jspa?threadID=1677617&start=45&tst
> art=0> &start=45&tstart=0
>
>  
>
> I can also attest to having severe eye strain from LED displays.
>
> I have spent countless long days staring at many types of monitors (CRT,
> LCD, Plasma) with no problems. Then, in January, I purchased a new Macbook
> Pro with an LED display only to realize that after about an hour I would get
> headaches and my eyes felt severely strained.
>
> I have used a combination of full spectrum desk lighting and frequent
> breaks, but I still cannot work on my computer all day like I used to. I
> didn't fully understand that it was LED technology causing the eye problems
> until my Dad purchased a new LED television recently, and I immediately
> experienced the same eye strain within a half-hour of watching his
> television.
>
> That experience led to more research and this thread, which confirms thatat
> least some others are experiencing issues with this display type.
>
> My advice to others is try out LED displays before purchasing because
> sensitivity can occur even if you've never had eye strain before. My only
> solution now is to either sell my Macbook Pro or buy an additional monitor,
> which will at least help with home work.
>
>  
>
>  
>
>  
>
>  
>
> This is a problem whether it's blinding the masses or not. I am glad that
> other people have reported a problem because I thought I was losing my mind.
> Don't know what I'm going to do because it's taken me more than two weeksto
> get to the bottom of this problem. I love Apple, but I also hate them. You
> get a few choice and live and die by those choices. I waited on the
> non-glare screen, but still the LED seems to be causing me a problem. Grrrr.
> I feel trapped.
>
>  
>
>  
>
>  
>
>  
>
> I get sore eyes, But i thought this was just because i had glasses, and to
> speak, I never had this problem with my iBook. The way i found to fix it is
> to 1. Turn the Brightness Down, 2. Blink More (You have to think about this
> when you are concentrating).
>
>  
>
>  
>
>  
>
>  
>
> Add me to the list of people strongly affected by this issue.
>
> I've been using computers since the Apple ][ days and typically spend hours
> per day in front of screen displays. I have never experienced anything like
> the nausea and headaches I've been feeling since I purchased the new Macbook
> Pro.
>
> It ranges from "unpleasant" to "completely debilitating". None of my other
> laptops or monitors have caused this problem before.
>
> Like many of you, I'm reluctant to give up what is an otherwise nice machine
> (and I'm out of my 14-day return window), but this is not something I can
> live with.
>
> If anyone has found anything that works for them, please share. I'm goingto
> do some experiments over the next few days with brightness settings, but I
> am not optimistic at this point.
>
>  
>
>  
>
>  
>
> Well, I had to give up the MacBook Pro. I'm working on one of the last
> MacBooks with an LCD screen. I got it yesterday. You see, Apple just
> announced that even MacBooks are now coming out with LED Backlit screens.I
> feel fortunate that I figured this out before the LCD screen became extinct.
> Yes, I miss my MBPro, but in a few days I'll adjust to the slightly slower
> speed and the smaller screen. My eyes definitely feel better. I visited my
> eye doctor yesterday before I made the decision and took my computer. She
> said that she noticed my eyes tearing up from the strain of the looking at
> the screen in just a few minutes. This is a real phenomenon and I hope Apple
> will make note and provide the LCD screen as an option.
>
> Having the non-glare screen on the LED seems to make no difference IF you
> are sensitive to the light generated by the LED technology. I had had my
> MBPro for about six weeks. It took time to identify what was causing the
> problem. I visited two Apple stores, taking material from the Internet, and
> managers at both places said they had "heard" something about this issue and
> would have no problem trading out the machine, in spite of the time.
>
> I waited until I saw my doctor, hoping she could prescribe some special
> glasses, but no. I returned to one of the stores and hoped to get a hard
> drive larger than the 160, but I would have to get that online. The store
> manager said I could do the exchange online with no problem. NOT TRUE. I
> went to my car and phoned Apple and was told that I was outside of the
> 14-day window, there was no swapping, and was there anything else I needed
> help with. I didn't see the point in mentioning the letter I had from the
> doctor or anything since I was right outside of a store and could get the
> computer that day, rather than wait, after begging. The manager of the store
> could not have been nicer. I was impressed.
>
> So, yes, I miss the MBP, but I've rationalized: My old iBook had 60 GB, so
> 160 is more than twice that. I had a 12" screen before, now I have 13". So,
> I didn't get to go state-of-the-art with the MBP, but my eyes aren't on
> fire.
>
> This is a real problem that a few, very light sensitive people have.
> Blinking and dimming the screen did not help. Deselecting the ambient light
> option did not help. There were certain lighting conditions where it didn't
> hurt as much, but that was a moving target trying to combine time of day,
> position of window blinds, and position of desk---hard to hit with a searing
> headache.
>
> Another option is to keep the MBP and get an external monitor. MBP works
> closed, a specialist told me, and you can sit the monitor on top of it. Get
> the magic and avoid the burn that way.
>
>  
>
>  
>
>  
>
> hey i bought my laptop from mac about a month ago
> and since then my vision has become very shaky
> and becoming worse and worse everyday
> when i drive when i try to focus on cars infront of me
> or to the left or right of me they seem to dissapear
> for a second then reappear and sometimes
> they seem to be doing a shutter movement
> day or night its the same thing
> i just got my eyes checked out to make sure it wasnt that
> the doctor said my eyes are perfectly fine
> i was doing some research yesterday
> and found all of you out there with the same problems
> im trying to return my macbook pro and they arent being coorperative
> i cant drive anymore because of how bad my vision has gotten
> and it doesnt seem like anyone at apple cares what so ever
>
>  
>
>  
>
> purchased the new LED monitor for my MacBook Air and it works great.
>
> However I have experienced severe headaches and feelings of nausea up to
> dissorientation. I am totaly confident that this is the monitor as my
> girlfriend and I were doing some work together on my monitor last night and
> she expereinced severe reaction with nausea and dizzyness. After 30 minutes
> away from the monitor she was fine. I have experienced this from the first
> day I got he monitor and it does this in any light conditions in the room,
> no matter how far I sit from it or light level settings.
>
> I dont want to give up the monitor but I feel sick every time I use it. The
> previous monitor I was using was the LCD version of the same monitor and it
> gave me no problem whatsoever.
>
> Apple - please address this - it is very real and people are feeling like
> they are getting the flu or sick.
>
>  
>
>  
>
>  
>
> Wow, I truly appreciate this post and all the people who have wrote back.I
> just bought the new 21.5 Imac and without realizing the screen difference
> between my March 2009 20"Imac and the new Nov 2009 21.5" Imac, I started to
> get a tense burning in my eyes the first few days of using it. I had never
> felt this before with the March 2009 20 inch Imac with the LCD screen that I
> had used for almost 1 year. I am now going to return the new one.
>
> I want someone to tell me that there is a fix because the new machine is a
> bit faster and of course it is "newer". However, there is none and the trade
> off does not compare. I thought I may be over reacting, but now as I am
> using the old one again the screen looks much softer and not so sharp andmy
> eyes are not hurting me any longer. Nothing more to be said!
>
>  
>
>  
>
>  
>
> I also was wondering if I was going blind or something.
>
> I used to have ccfl macbook pro but it got stolen.
>
> After reading text on my recently purchased used macbook pro my eyes would
> shift out of focus and I felt like I was tripping on something for a few
> seconds. Then it goes away. And then it would happen again. Obviously some
> kind of sync or refresh issue. This doesn't happen to me viewing anything
> else.
>
> Yeah so it almost makes the laptop useless for reading text.
>
> One thing that helps is speed reading. If I read almost too fast it doesn't
> happen as much. But if I leisurely read it will go all unfocused.
>
> I have a feeling newer versions have better technology and do not do it as
> much. Oh there it goes I'm going all cross eyed again or whatever. This is
> frustrating!
>
>  
>
>  
>
>  
>
> I bought my macbook just when it came out in October 2008. It has the
> led-backlit glossy screen. I have noticed that over the past year, my
> eyesight has worsened and that seeing long-distance is especially worse off
> than before. I have also gotten intense headaches, something that I have
> never experienced before purchasing the macbook.
> I think that my usage of the macbook, that is, looking at the computer
> screen for several hours a day for the past year has affected my eyesight.
> Permanently? I'm not sure. If I'm able to change my screen to matte, and I
> have noticed that I can see normal then I will post back on this forum
> again.
>
>  
>
>  
>
>  
>
>  
>
> have an imac and have experienced what I guess is eye strain ever since
> getting it. Eye feels like it is pulling or my face can literally
> ache....dry eyes....gee, it has sure changed my computer experience. I have
> been to the eye dr. and he found no changes in my eyes. So I have just been
> winging it and hoping to hear something similar to help me with my problem.
> I am lowering the brightness, changing to white on black background when I
> can, wearing sunglasses....eyedrops.....geez.....it almost seems like APPLE
> should have a complaint page about this issue. Not sure about this changing
> the gamma setting?? Any more input is greatly appreciated!
>
>  
>
>  
>
>  
>
>  
>
> Anyway, what I wanted to share is the fact that the chopper circuit that
> controls the LED backlight dimming is operating at a far higher frequency
> than have been previous versions of LED backlit panels in Apple's notebooks.
> In fact, it looks to my eyes to be an order of magnitude higher, which would
> mean higher than 3 kilohertz switching. This is really good news. The
> frequency is so high that normal phosphor decay dominates the operating
> characteristic of the white LEDs in dimming mode, and not the switching
> frequency as was the case before. That puts LED backlit LCDs much more on
> par with previous generation CCFL backlit LCDs, and perhaps even better
> than, at least with respect to this particular type of flicker.
>
> If people really were suffering ill effects from the lower blinking
> frequency of the LEDs before, then the new ones should start reducing the
> number of complaints about eyestrain, headaches, dizziness, nausea, etc.
> that have been seen on these discussion forums. Time will tell. But I'm
> really encouraged by this development. Someone is listening somewhere.
>
>  
>
>  
>
>  
>
>  
>
> For all of you doubters out there. I replaced my LED screen for a non-LED
> screen and the eye strain headaches were gone instantly. 100% gone!
> No doubt about it.
>
> cont... I just want to emphasize that I traded in my LED glossy screen for
> a non-LED glossy screen. My eye strain headaches were gone instantly and I
> have never seen them since despite the fact that I am still using a glossy
> screen.
>
> Oh, and by the way, I went to the eye doctor recently and my eyes are
> approximately the same as they have always been.
>
> There is no doubt that LED was giving me a miserable headache. Perhaps it
> was me and not all users will have the same reaction. But, with that being
> said, I would urge all to take caution with the new LED screens.
>
>
>
>
>  
>
>  
>
>  
>
> _____  
>
> From: [hidden email] [mailto:[hidden email]] On Behalf Of
> svetaswan
> Sent: 11 May 2010 05:40
> To: [hidden email]
> Subject: [eSens] Anyone here flicker sensitive?
>
>  
>
>  
>
> Hi all,
>
> Twice, I've done Richard Conrad's flicker-sensitivity test - where I put a
> dark towel over my laptop's screen to test my response. Both times, I
> noticed a definite relief - a type of "destressing" of my brain (possiblymy
> eyes, too). This certainly doesn't mean that "flicker sensitivity" is
> responsible for all of my "computer woes" - but apparently, it is part of
> the problem.
>
> Great - so whenever I'm in front of this screen, my brain is having little
> seizures. Life is good. ;-/
>
> Anyway, this realization led me to try to look up information on the screen
> that's attached to this laptop. Such information is quite hard to come by
> (Dell doesn't even seem to give any information about the screen in the
> User's manual or its official listing of specs) - but I managed to come
> across a site that listed this screen's refresh rate as being 60Hz, and its
> "response time" as being 25ms ("rise") to 35ms ("fall"). From what I know
> about LCD displays, a 25ms response time is quite a bad number - it seems
> that the absolute maxium response time for a LCD to be considered any good
> is 8ms.
>
> But my question is, how does response time contribute to flicker
> sensitivity? Does a "slow" response time contribute any to flicker/screen
> sensitivity, or is it all about refresh rate?
>
> Does response time factor into the equation when you're, say, reading
> webpages or watching YouTube? Could the slow response time be contributing
> to my screen sensitivity?
>
> Oh, and I also dim the screen - because of my sensitivity/intolerance to
> screen brightness. Could the dimming of the screen be contributing in some
> way to my brain's adverse response to this display? (Because of the
> "chopping" effect?)
>
> Considering my apparent flicker sensitivity, should I look for a LCD witha
> 85Hz or greater refresh rate, or would it be sufficient if I just found one
> with a low (say, 5ms) response time? LCD monitors with low response times
> are relatively easy to come by these days - LCDs with a greater than 60Hz
> refresh rate are harder to come by (and more expensive).
>
> For those of you flicker sensitive, what has worked for you as far as LCD
> monitors go? Is finding a montior with 85Hz-or-greater refresh rate
> absolutely essential - or could you "cover" for a 60Hz refresh rate by
> getting a display with a relatively-low resolution, and/or a low
> response-time? What size screen, and other screen parameters, have worked
> for you?
>
> Any and all responses welcome (there may be some of you who are not flicker
> sensitive, but who may have knowledge on this topic). Thanks in advance,
>
> ~Svetaswan
>
>
>
>
>
> [Non-text portions of this message have been removed]
>