RMartin111

Q: Eye strain from LED backlighting in MacBook Pro

There is one relatively serious con of the new LED backlit displays in the new MacBook Pros that seems to not get too much mention in the media. About a month ago I bought a new MacBook Pro to replace my standard white MacBook. One feature of the MacBook Pro that I was unaware of was the introduction of the LED backlit display to replace the CCFL backlight.

Once I started using my new laptop for long periods of time, I noticed severe eye strain and minor symptoms almost similar to motion sickness. After 20 or 30 minutes of use, I felt like I had been looking at the screen all day. Much longer and I would get headaches. If I used the old white MacBook (with its CCFL display), I had no eye troubles at all. Moreover, I could detect a distinct flicker on the MacBook Pro display when I moved my eyes across it - especially over high contract areas of the screen. White text on a black background was virtually impossible for me to read without feeling sick to my stomach because of all the flickering from moving my eyes over the text.

The strangest thing about all of this was that nobody else I showed the screen to could see these flickers I was seeing. I began to question my sanity until I did a little research. Discovering that the MacBook Pro introduced a new LED backlit display started to shed some light (so to speak) on what might be going on. I had long known that I could see LED flicker in things like car taillights and christmas lights that most of my friends could not see. I also knew that I could easily see the "rainbow effect" in DLP televisions that many other people don't see.

My research into LED technology turned up the fact that it is a bit of a technological challenge to dim an LED. Varying the voltage generally doesn't work as they are essentially designed to be either on or off with a fixed brightness. To work around this limitation, designers use a technique called pulse width modulation to mimic the appearance of lower intensity light coming out of the LED. I don't claim to fully understand the concept, but it essentially seems to involve very briefly turning off the LED several times over a given time span. The dimmer the LED needs to appear, the more time it spends in the off state.

Because this all happens so very quickly, the human brain does not interpret the flickers as flickers, rather as simply dimmer light. For most people that is. Some people (myself included) are much more sensitive to these flickers. From what I can tell, the concept is called the "flicker fusion threshold" and is the frequency at which sometime that is actually flickering is interpreted by the human brain as being continuously lit. While the vast majority of people have a threshold that doesn't allow them to see the flicker in dimmed LEDs, some people have a higher threshold that causes them to see the flickering in things like LED car tail lights and, unfortunately, LED backlit displays - leading to this terrible eye strain.

The solution? I now keep my screen turned up to full brightness to eliminate the need for the flicker-inducing pulse width modulation. The screen is very bright, but there are no more flickers and I love my MacBook Pro too much to exchange it for a plain MacBook with CCFL backlighting (which will also supposedly be switching to LED backlighting in 2009 anyway.) The staff at my local Apple store was of course more than helpful and was willing to let me exchange my glossy screen for matte even though I was beyond the 14 day return period. I knew that wasn't the problem though as my old MacBook was a glossy display. I've decided to stick with my full brightness solution. Sitting in a brightly-lit room tends to help alleviate how blinding the full brightness of the screen can be. In a dimly-lit room I guess I just wear sunglasses. Either way, the extreme brightness is worlds better than the sickening flicker I saw with a lower brightness setting

I would caution anybody considering buying a product with an LED backlit display to pay careful attention to make sure you don't have this same sensitivity. Turn the screen brightness down, find a high contract area of the screen, and quickly move your eyes back and forth over the screen. If you can detect the flicker, you may end up with this same problem.

I have no idea what percentage of the population has this sensitivity. I imagine we will hear more about it as more and more displays start using this technology. Hopefully the Apple engineers will come up with a way to eliminate this flicker some of us can see.

Russ Martin

15-inch MacBook Pro, Mac OS X (10.5.4)

Posted on Aug 23, 2008 8:25 AM

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Q: Eye strain from LED backlighting in MacBook Pro

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  • by tight_eye,

    tight_eye tight_eye Jan 21, 2014 10:37 AM in response to mvanier
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    Jan 21, 2014 10:37 AM in response to mvanier

    @mvanier: Which Macbook do you own? So far I've read threw the thread and the oberverations and they are familiar to me right now. In terms of Ubuntu being darker I think it is not hitting the point. I'm not pretty sure that it is the dithering because I think on the MB Pro and Pro Retina it must be pretty the same. And for first impression I think the MB Pro displays just pleasing content for my eyes and it is not the bigger font size. There is just no latense swirling which disturbs my eyes. Sounds like described dithering. Hm.

     

    Edit: What I completely messed up to mention is that I had the same eye problems with a lenovo Full HD Display being 13". I couldn't look at it for longer than 10 minutes which makes me consider the resolution being a factor again. But then why doesn't the eyestrain go away when zoomed in in Safari.

  • by mvanier,

    mvanier mvanier Jan 21, 2014 3:37 PM in response to tight_eye
    Level 1 (0 points)
    Jan 21, 2014 3:37 PM in response to tight_eye

    @tight_eye: The MacBook is a 13" non-retina model with only Intel graphics chips (no Nvidia).  Ubuntu is indeed darker than OS X but I doubt that that's the probllem, plus there is the bit about high contrast helping on Mac OS X.  Also, there are many ways to do dithering.  What is usually called "temporal dithering" is almost always spatiotemporal dithering, with many adjacent pixels participating and flickering to give the final effect.  This could easily give different results on the Retina display vs the regular one.  The Retina display could be worse or better, depending on how the algorithm was implemented.

  • by dmendel,

    dmendel dmendel Jan 21, 2014 4:41 PM in response to dmendel
    Level 1 (0 points)
    Jan 21, 2014 4:41 PM in response to dmendel

    dmendel wrote:

     

    dmendel wrote:

     

     

    I  just ordered a new Mac Mini and a Benq GW2450HM (same specs as the one noted above). Should have everything set up and tested  within the next 10 days. I will report back my experience. As I have noted in this thread, I could not tolerate the new 27" iMac. I was going to get a refurbed Dell U2410, which is CCFL, based on some users' suggestions, but turns out I wasn't able to get it. So I went with what looks to be the next best thing (at least on paper). I wanted to avoid W-LED, but the Benq has a "low blue light" mode that seems to work (see the review at http://pcmonitors.info/reviews/benq-ew2740l). Some people have recommended the new Dell 2713, which uses a GB-LED, but the 6-bit+FRC turned me off. If the Benq does not pan out, then I might try that. Hopefully the Benq will be true to its claims. Fingers crossed.

     

    Well everything arrived and set up. The monitor immediately caused the same tension and tightening in my eyes as the iMac. Not as intense, but still there. However, I quickly realized that something was amiss. The OSD menus did not match what I had read on TFT Central. None of the pre-set modes, like "Low Blue Light" could be found. I double-checked the part number and realized that I had an older model that is not the updated flicker free design. I have to return it and try to get my hands on a flicker-free model.  

     

    That said, I am not at all impressed with the image quality of the monitor, flicker or no. The text is not very sharp and is noticebly more pixelated than my old 2006 20" iMac that i am currenlty still using. For example, The "W" in Window in the finder menu bar at the top is very jagged. Looks pretty bad. If the newer flicker-free models are essentially the same image quality it will be disappointing. But if they don't cause discomfort, I can live with it.

     

    So, I will report back when I get my hands on the flicker-free model. 

     

     

    I am having trouble locating one of the flicker-free monitors here in Canada. The only one I could find is the EW2440L, which they happen to have at a local shop. But I just came across a refurbished HP LP2475W. This is one of the early IPS panel displays but is CCFL backlit. According to TFT Central it is a 24" WS LG.Display H-IPS. It is the same price (slightly cheaper actually) as the new Benq, and can be returned with no "restocking fee" (unlike the Benq), so I decided to order it and see what it is like. Out of curiosity. Has anyone here had any experience with those early-IPS CCFL HP monitors? (I also had the possibility of getting a refurbed ZR24W for the same price, but I was put off by reviewers' complaints of the extreme brightness at the lowest setting.) If that does not work, I will try out the Benq.

  • by Jessiah1,

    Jessiah1 Jessiah1 Jan 22, 2014 7:22 AM in response to mojarvinen
    Level 1 (0 points)
    Jan 22, 2014 7:22 AM in response to mojarvinen

     

     

     

     

    XTi should do it if it has video.

     

    Unfortunately my XTI does not have video, if anyone here owns one of the cars with LED accent lighting around the headlights (AUDI is good) ,and a camera that can record at the frame rate mojarvinen suggested, could you take a video of them to look for flicker? Thanks in advance if you can!!

     

    On another note I wanted to share this article which I thought was interesting about the incandescent bulb, I don't think the industry cares but I thought some here would find it interesting if you have issues with fluorescent and LED home lighting:   http://www.foxnews.com/science/2014/01/16/congress-offers-glimmer-hope-for-incan descent-light-bulb/

     

     

    Jesse

  • by Jessiah1,

    Jessiah1 Jessiah1 Jan 22, 2014 7:30 AM in response to dmendel
    Level 1 (0 points)
    Jan 22, 2014 7:30 AM in response to dmendel

    dmendelI am having trouble locating one of the flicker-free monitors here in Canada. The only one I could find is the EW2440L, which they happen to have at a local shop. But I just came across a refurbished HP LP2475W. This is one of the early IPS panel displays but is CCFL backlit. According to TFT Central it is a 24" WS LG.Display H-IPS. It is the same price (slightly cheaper actually) as the new Benq, and can be returned with no "restocking fee" (unlike the Benq), so I decided to order it and see what it is like. Out of curiosity. Has anyone here had any experience with those early-IPS CCFL HP monitors? (I also had the possibility of getting a refurbed ZR24W for the same price, but I was put off by reviewers' complaints of the extreme brightness at the lowest setting.) If that does not work, I will try out the Benq.

     

    I am still wondering about one thing and have asked several times without someone here who is an expert in electricity providing an explanation, maybe Artichoke could answer?:

     

    If the power coming into your monitor is inconsistent, or pulsing couldn't it create a flicker in a flicker free monitor?

     

    The reason I bring this up is because if pulsing power delivery has been an issue all along with monitors and household lighting, with the addition of extremely bright LED back lighting that can pulse completely on/off wouldn't that explain why a flicker free monitor could still bother some of us? Can anyone do an experiment with some sort of power filtering device to plug a "flicker free" monitor into? I haven't seen this discussed and I am no PHD in electrical engineering but it seems important maybe?

     

    Thanks,

     

    Jesse

  • by spprt,

    spprt spprt Jan 24, 2014 10:04 AM in response to RMartin111
    Level 1 (0 points)
    Jan 24, 2014 10:04 AM in response to RMartin111

    Because I had read some posts here about how earlier iPhone displays potentially caused no problems, I recently bought a used iPhone 4 from 2010. The symptoms are gone!

     

    I hope this is no coincidence, but for me it works. Now I have an iPhone that I can use all day.

     

    There is on thing though: Safari on iOS 7 is a little worse on the eyes than other apps. I think they use a special 3D accelerated mode for the new Safari. I feel the same on my iPad 4, just a lot stronger.

     

    Before, the iPhone 4 has been on iOS 6. I tested everything there, even Safari on iOS 6 is no difference from other apps and very good for my eyes.

     

    So, if you suffer from LCD eye strain but want an iPhone, I suggest you buy an old iPhone 4 that has still iOS 6 on it.

    Hope this helps anyone.

  • by tight_eye,

    tight_eye tight_eye Jan 25, 2014 8:57 AM in response to RMartin111
    Level 1 (0 points)
    Jan 25, 2014 8:57 AM in response to RMartin111

    It's funny cause I too have no problems with the iPhone 4(S) as mentioned above. The eyes truely relaxe on the screen when I read even really long articles.

     

    BUT I like to share my thoughts on the MBP13 which arrived two days ago. Unfortunately it is bad as the MBA I've previously owned. I can't help but it seems like the white background almost creates a cloudy fuzzy effect around black letters. This makes reading text an incredible pain. I am really angry about Apple not helping us out. I want a Mac and it's just an awesome machine but what can someone do who feels serious pain from every single machine they provide?

     

    I mean it's so severe, that the cloudy fuzzy feeling from staring at the display transfers immediately to my normal look away from the display. Everything swirls around, eyes are definitely tired and hesitate from finding appropriate focus in any manner. **** this is driving me crazy.

  • by dmendel,

    dmendel dmendel Jan 26, 2014 12:02 PM in response to dmendel
    Level 1 (0 points)
    Jan 26, 2014 12:02 PM in response to dmendel

    dmendel wrote:

     

    dmendel wrote:

     

    dmendel wrote:

     

     

    I  just ordered a new Mac Mini and a Benq GW2450HM (same specs as the one noted above). Should have everything set up and tested  within the next 10 days. I will report back my experience. As I have noted in this thread, I could not tolerate the new 27" iMac. I was going to get a refurbed Dell U2410, which is CCFL, based on some users' suggestions, but turns out I wasn't able to get it. So I went with what looks to be the next best thing (at least on paper). I wanted to avoid W-LED, but the Benq has a "low blue light" mode that seems to work (see the review at http://pcmonitors.info/reviews/benq-ew2740l). Some people have recommended the new Dell 2713, which uses a GB-LED, but the 6-bit+FRC turned me off. If the Benq does not pan out, then I might try that. Hopefully the Benq will be true to its claims. Fingers crossed.

     

    Well everything arrived and set up. The monitor immediately caused the same tension and tightening in my eyes as the iMac. Not as intense, but still there. However, I quickly realized that something was amiss. The OSD menus did not match what I had read on TFT Central. None of the pre-set modes, like "Low Blue Light" could be found. I double-checked the part number and realized that I had an older model that is not the updated flicker free design. I have to return it and try to get my hands on a flicker-free model.  

     

    That said, I am not at all impressed with the image quality of the monitor, flicker or no. The text is not very sharp and is noticebly more pixelated than my old 2006 20" iMac that i am currenlty still using. For example, The "W" in Window in the finder menu bar at the top is very jagged. Looks pretty bad. If the newer flicker-free models are essentially the same image quality it will be disappointing. But if they don't cause discomfort, I can live with it.

     

    So, I will report back when I get my hands on the flicker-free model. 

     

     

    I am having trouble locating one of the flicker-free monitors here in Canada. The only one I could find is the EW2440L, which they happen to have at a local shop. But I just came across a refurbished HP LP2475W. This is one of the early IPS panel displays but is CCFL backlit. According to TFT Central it is a 24" WS LG.Display H-IPS. It is the same price (slightly cheaper actually) as the new Benq, and can be returned with no "restocking fee" (unlike the Benq), so I decided to order it and see what it is like. Out of curiosity. Has anyone here had any experience with those early-IPS CCFL HP monitors? (I also had the possibility of getting a refurbed ZR24W for the same price, but I was put off by reviewers' complaints of the extreme brightness at the lowest setting.) If that does not work, I will try out the Benq.

     

    Well, bad news to report. I have been working today with the new (refurbed) HPL2475W and it is not good. It is definitely better than the LED iMac -- there is none of that shimmering and inability to focus on text, and the tightness in the eyes is much less intense. But there is still some tightness in the eyes, light-headedness, and slight nausea. As soon as I turn to my old iMac or Macbook the unpleasant sensation is instantly gone. I am going to connect the monitor to my iMac and Macbook and see if the effects are the same, but I have to do this tomorrow. Unfortunately I have no older style mini DVI to DVI adapter to connect to the HP. I have a mini DVI to VGA cable at the office that I use to connect my older Macbook to a projector for presentations. I will use that and connect to a VGA-DVI-I cable that came with the monitor. I hope that will work. I will report back tomorrow with the results. But I am now really thinking that my problem is OS-based and not necessarily hardware/display based. If so, that is very, very depressing. I will have to abandon Apple after 25 years of loyal use.

     

    By the way, in case anyone cares: the problem with the resolution on the BenQ was due to the HDMI connection. I had the same problem with the HP when I connected using HDMI. Quick search revealed that this is common and long-time problem with the late-2012 Minis. Using the supplied HDMI to DVI adapter with a DVI cable solved the problem and produced a clear, crisp image.

  • by SimonStokes,

    SimonStokes SimonStokes Jan 26, 2014 2:30 PM in response to dmendel
    Level 1 (0 points)
    Jan 26, 2014 2:30 PM in response to dmendel

    Thanks for reporting back on your experiences. Just to update everyone with my situation:

     

    After 2 years of searching, swapping Macbook screens, trying out different LED monitors and generally suffering pretty badly I realised that the solution was incredibly simple: I'm LED sensitive. So don't use LED screens. :]

     

    I tried the Benq GW2460HM Flicker-Free monitor as my last resort but experienced the same eye strain, nausea and migraines that I get with other LED screens (to wildy different degrees). So last week, I bought a Benq G2420HD CCFL monitor, and now that my migraine symptoms have gone I feel like brand new again.

     

    No more migraines, no more eye strain, no more tiredness, no more sleepless nights, no more DIY laptop repairs, no more searching, no more trying to grapple hardcore TFT display science. So if you're struggling for a solution and it's affecting your life like it was mine, just go back to CCFL - I got this monitor for £70 from eBay - cheaper and much, MUCH better!!

     

    I hope everyone else finds their solutions and I'll be keeping my eye on this thread for more developments.

  • by dmendel,

    dmendel dmendel Jan 26, 2014 6:04 PM in response to SimonStokes
    Level 1 (0 points)
    Jan 26, 2014 6:04 PM in response to SimonStokes

    SimonStokes wrote:

     

    Thanks for reporting back on your experiences. Just to update everyone with my situation:

     

    After 2 years of searching, swapping Macbook screens, trying out different LED monitors and generally suffering pretty badly I realised that the solution was incredibly simple: I'm LED sensitive. So don't use LED screens. :]

     

    I tried the Benq GW2460HM Flicker-Free monitor as my last resort but experienced the same eye strain, nausea and migraines that I get with other LED screens (to wildy different degrees). So last week, I bought a Benq G2420HD CCFL monitor, and now that my migraine symptoms have gone I feel like brand new again.

     

    No more migraines, no more eye strain, no more tiredness, no more sleepless nights, no more DIY laptop repairs, no more searching, no more trying to grapple hardcore TFT display science. So if you're struggling for a solution and it's affecting your life like it was mine, just go back to CCFL - I got this monitor for £70 from eBay - cheaper and much, MUCH better!!

     

    I hope everyone else finds their solutions and I'll be keeping my eye on this thread for more developments.

     

    Simon, it is great to hear you have found something that works. Of course the HP LP2475W is CCFL as well, but doesn't seem to work for me. Like I said, symptoms are much less than with LED, but still not as symptom-free as my old 2006 iMac or 2008 Macbook. Maybe I need to try a monitor with a "cheaper" CCFL TN panel (like the BenQ G2420HD). That's what I currently use and it works for me. Problem is finding one.

  • by kvoth,

    kvoth kvoth Jan 26, 2014 6:34 PM in response to SimonStokes
    Level 1 (0 points)
    Jan 26, 2014 6:34 PM in response to SimonStokes

    Congrats, Simon That's great to hear. Feels great, doesn't it?

  • by SimonStokes,

    SimonStokes SimonStokes Jan 27, 2014 1:44 AM in response to dmendel
    Level 1 (0 points)
    Jan 27, 2014 1:44 AM in response to dmendel

    dmendel wrote:

    Simon, it is great to hear you have found something that works. Of course the HP LP2475W is CCFL as well, but doesn't seem to work for me. Like I said, symptoms are much less than with LED, but still not as symptom-free as my old 2006 iMac or 2008 Macbook. Maybe I need to try a monitor with a "cheaper" CCFL TN panel (like the BenQ G2420HD). That's what I currently use and it works for me. Problem is finding one.

    I'm sorry to hear that you've yet to find a solution - I have found that the two screens that I can use without any symptoms are: Benq V2400W and Benq G2420HD. I'm assuming that other cheap Benq CCFL monitors will use the same or similar backlight but that's difficult to know.

     

    When I first connected this current monitor it was shimmering badly but as soon as I changed it to 1080p instead of 1080i it was perfectly crisp, connected by HDMI. I have to teach people using Apple products all day, and the newer iMacs are always a killer for me. The OS is exactly the same as on my Macbook though so I don't see why you should encounter problems with the right panel. Give the Benq ones a bash and I'll keep my fingers crossed for you..

     

    Now all I need is a replacement for my iPhone 4 that I can use!

  • by tight_eye,

    tight_eye tight_eye Jan 27, 2014 5:46 AM in response to SimonStokes
    Level 1 (0 points)
    Jan 27, 2014 5:46 AM in response to SimonStokes

    @SimonStokes: Glad to hear you found a personal solution.

    For myself I can report that I was able to work with a Sony Vaio VPCY 11S1E/S for nearly 4 years without any symptoms at all. A quick research told me that this machine also uses LED. So for me it must be a different problem or at least Apple using other LEDs than Sony does. Unfortunately I'm suffering from a lenovo thinkpad yoga screen too as already reported some posts ago.

    I can't understand and accept that this is a general problem with LED at least in my case.

     

    But I can tell that working with the MBP 2012 is a latent pain in the *** for me. This Laptop is definitely going back soon. Today I made the decision to give the new rMBP late 2013 a try even though there seems no other display installed than before but I've read that the strange magenta cast isn't as present on these machines anymore.

     

    The fact that some of rMBPs, especially from 2012, have pink/magenta shining apple logos on the back makes me wonder whether this is truely a personal issue.

     

    FYI I had minor symptoms with MB Airs so far. The quality of eye strain is different on these machines imo. I cannot say that it is without issues or even comfortable but I absolutely love Macbooks and would pick a Haswell Air if this rMBP late '13 will also fail for me.

  • by mvanier,

    mvanier mvanier Jan 27, 2014 1:03 PM in response to SimonStokes
    Level 1 (0 points)
    Jan 27, 2014 1:03 PM in response to SimonStokes

    Simon,

     

    I'm glad you found a solution that works for you.  What is the make of your computer and the OS version?  These are very important to know because it makes a huge difference.  My old MacBook running Snow Leopard works fine with any external CCFL-backlit monitor but my new MacBook running Mavericks gives me severe eyestrain with the very same monitors.

     

    I discovered something interesting today.  The quality of eyestrain I get when running my Macbook and Mavericks is very different from the quality of eyestrain I get running Ubuntu Linux on the very same computer.  With the Macbook it's the "snow" effect, which is very distracting and causes my eye muscles to get sore quite quickly, probably because my eyes are subconciously following the snow.  This is quite likely to be due to temporal or spatiotemporal dithering, as it persists when the computer is connected to an external monitor.  Unfortunately there is no way to turn it off short of going to grayscale and using very high contrast (which helps quite a bit).  On Ubuntu this problem doesn't exist, but there is a different one.  It might be due to PWM or something that causes intensity spikes in the backlight.  Possibly a flicker-free monitor would get rid of the symptoms for Ubuntu but probably not for Mac OS X.  It may be that you can learn to mentally tune out the "snow" over time, but it is really annoying.

  • by OQ3,

    OQ3 OQ3 Jan 27, 2014 2:08 PM in response to mvanier
    Level 1 (0 points)
    Jan 27, 2014 2:08 PM in response to mvanier

    Some TVs and maybe monitors allow you do disable FRC/Dithering in their service menu. But it will probably void your warranty and some settings are extremely dangerous to the monitor.

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