Eye strain from LED backlighting in MacBook Pro

As i said before there are different screens manufacters for the HTC One.

http://forum.xda-developers.com/showthread.php?t=2202869

In this image below, this are not my phones, but the image fullfils the purpose:

https://dl.dropboxusercontent.com/u/548546/IMG_0028.JPG

My second screen is similar to the right one, cooler. One thing i notice is the rainbow effect. It's much more prounanced on the second one. I notice on my new screen but never on the old one. You'll see below later what i am talking about...

My screen:

m7_panel_init panel ID = PANEL_ID_M7_SHARP_RENESAS_CMD

m7_panel_init: PWM IC version A2

I dont know if the PWM it's about Pulse-width-modulation, so i just wanted to check. First i tried with shutter speeds of 1/25 and 1/8. Nothing all smooth.

So i tried 1 second, even if it didn't make any sense, and to my utter suprise i found this:

low brightness

http://imageshack.us/a/img43/6748/rt7k.jpg

http://imageshack.us/a/img843/1034/48j8.jpg

this not make any sense... i count 10 lines. This means PWM of 10hz?????

This is really weird... Shouldn't i notice on naked eye?

Then i tried full brightness:

http://imageshack.us/a/img209/5106/5epd.jpg

In this photo i had a higher ISO so, it's more smooth:

http://imageshack.us/a/img10/9291/p6pm.jpg

you can see near the top some colours... just a curiosity...

This PWM is really strange... around 10Hz. altough i dont understand if the light fully stops or not.

What puzzle's me it's the led's on the bottom of the phone also appear to have this frequency, so maybe it's just me, who's just doing something wrong.

Now in this 2 pictures:

http://imageshack.us/a/img854/6109/bhmi.jpg

http://imageshack.us/a/img801/2758/b5x3.jpg

you could see the polorised effect, but with colors. Live it's much more visible then on photo. If put the glasses and watch my monitor 27'' LED i just see white or black as i move my head... but on the phone it's full of rainbow colours...

What is helping you tremendously? the glasses and greyscale? How do you make it greyscale?

I'm very glad that you've gotten significant relief of your symptoms by switching to grayscale. It didn't work for me, but whatever works for you is good for you. On the other hand, do you want to be restricted to grayscale for all of your computing? If that were the case, I would start to look for alternatives to Apple. Also, I disagree with your statement that "grayscale can get rid of dithering". Dithering is simply a way to simulate colors (whatever their hue) that the hardware cannot produce directly by alternating colors that it can. Grayscale shrinks the 24-bit RGB color space (not counting the alpha channel) to an 8-bit space, which gives 256 grayscale levels. If you want 10-bit grayscale (1024 levels), for some colors you would need to dither between two grayscale levels, potentially leading to the same "snow" pattern that causes eyestrain, depending on the details of how the dithering is done. Now, what is possible is that grayscale in conjunction with high contrast might work (again, depending on how high contrast is implemented), but high contrast even without grayscale might work too.

On a completely different note, I purchased the Prevencia coating for my glasses, and I haven't found it to have made any difference at all. Perhaps it's keeping my eyes safer than they would be without it, but I don't notice less eyestrain. OTOH I always use f.lux so there probably isn't much extra blue light coming from my monitor anyway.

mvanier, Are you sensitive to fluorescent lighting in stores as well or only just LED screens?

tfouto wrote:

What is helping you tremendously? the glasses and greyscale? How do you make it greyscale?

The glasses help me in everyday tasks, such as when I go into a store or gym that has bad overhead lighting. They don't "fix" things outright, but they make them easier. But even with the glasses on, troubling LED screens continue to cause issues, though not as bad as without them.

The grayscale on my 2013 macbook pro retina display completely fixes the strain on my eyes. Without grayscale, I get severe symptoms. With it on, I have no issues. When I use my older external monitor, the Dell U2410, I can have color on without severe symptoms.

To turn on grayscale on OSX go to System Preferences -> Accessibility -> Use Grayscale.

mvanier wrote:

do you want to be restricted to grayscale for all of your computing?

I'm just trying to help others out. Grayscale computing > no computing.

If that were the case, I would start to look for alternatives to Apple

LEDs are not unique to Apple.

Also, I disagree with your statement that "grayscale can get rid of dithering". Dithering is simply a way to simulate colors (whatever their hue) that the hardware cannot produce directly by alternating colors that it can. Grayscale shrinks the 24-bit RGB color space (not counting the alpha channel) to an 8-bit space, which gives 256 grayscale levels. If you want 10-bit grayscale (1024 levels), for some colors you would need to dither between two grayscale levels, potentially leading to the same "snow" pattern that causes eyestrain, depending on the details of how the dithering is done.

As you say, if you limit the grayscale to a space that your monitor supports natively in the hardware then you are eliminating dithering.

On a completely different note, I purchased the Prevencia coating for my glasses, and I haven't found it to have made any difference at all. Perhaps it's keeping my eyes safer than they would be without it, but I don't notice less eyestrain. OTOH I always use f.lux so there probably isn't much extra blue light coming from my monitor anyway.

f.lux changes the hue of color. It will not eliminiate ultraviolet light nor reduce flicker. I think we should end the conversation on f.lux, it is not a solution.

Jessiah, fluorescent lights don't bother me at all. The very old mechanical-ballast ones that flicker at 60 Hz do bother me but the only place I've seen them in the past few years is our local DMV (dept of motor vehicles), which is just one of many reasons to avoid that place :-) Even LEDs don't bother me that much; I have an iPhone 4S which initially bothered me but I got used to it. LED light bulbs do bother me, though some of them are because of flicker (Cree) and others because of color (Philips).

My real problem is flicker, which I am acutely sensitive to.

Kvoth, LEDs are not unique to Apple, and I never said they were. In fact, the whole conversation about LEDs seems to me to be completely misguided, as they are not the primary problem for most of us as far as I can tell (including you), although as you say they may make a bad situation worse. I'm actively looking into Linux as an alternative because I can control the graphics drivers on Linux in a way that is impossible with Apple or Windows (yay for open source!). You may not need this or want to go this way. I'm glad you've found an approach which works for you, and it's fine to let others know in the event that it works for them too, but there are a lot of us here, each with their own particular issues. BTW I've tried my Macbook with two different CCFL-backlit external monitors, and the flicker and eyestrain was still there, even with grayscale.

mvanier --

When did you first start experiencing these issues?

Jessiah has a theory that some people have flicker/spectrum sensitivity, and some have EMF sensitivity. Any chance you're in the EMF camp?

Kvoth,

I'm definitely flicker sensitive and somewhat sensitive to blue light, that's all. I think I've always been this way, but I've only noticed it in the past couple of years with these new monitors/drivers.

Mvanier, it is interesting that your sensitive to the lower frequencies, very similar in fact to the range which is known to cause epileptic seizures. Kvoth and myself are sensitive to a wider range of frequencies reaching into the supposed to be invisible to the eye level. Fluorescent lighting is an issue for both of us and that is where the Provencia anti-glare coating is very effective while with LED it may only help by adding just a few minutes of tolerance.

I believe it would be very difficult to say the exact percentage of people here who have the exact same sensitivity to the exact same triggers. Without the anti-glare coating fluorescent lighting makes me just as sick as LED lighting so my level of sensitivity is much greater than yours, LED lighting of any kind triggers migraines almost instantly.Sometimes they go away if I remove myself from exposure quickly but I can feel it starting instantly so I have 0 tolerance to LED. My symptoms are more than eye strain, nausea, fatigue, balance issues, brain dysfunction and many more symptoms.

My symptoms can last for days and I have met several other people who have almost exactly the same level of pain as myself, I would say that your not even close, so why is that? Why do you have some reaction but can tolerate some LED usage and no reaction to fluorescent lighting?

One thing is certain for me (myself being a good measure since I am the extreme), flicker and spectrum are an issue. There are some very blue and bright white fluorescent lamps which are almost as bad as LED lamps for me, but if spectrum were the only issue than why do yellow LED's bother me and fire places? There is plenty of scientific info out there showing increased flicker from blue spectrum lighting, is it that the bight white and blue spectrums flicker more for some reason? I am no scientist but from what I have read this makes sense and Kvoth is getting somewhere with the "Square" light info.

It may be that modern image rendering and dithering are adding to the issue but the LED lighting is the source of the intensity for sure and science will show that, I am sure of it. I have read hundreds of pages about this, I will leave you with this paper link on different lighting tests, check out the results from all the different light sources tested and see the potential for flicker in "Solid state lighting" compared even to fluorescent and also the most pleasant light source, incandescent:

http://www.e3tnw.org/Documents/2011%20IES%20flicker%20paper%20poplawski-miller-F INAL.pdf

I hope this deeper detail about myself and this article help bring some new topics to light:)

Jessiah, I'm sorry you have such severe issues. It certainly puts my more modest issues into perspective.

I have had a severe negative reaction to a yellow LED light bulb (Cree) but that was not because of the color, which was quite pleasant; it was because the light flickered at 120 Hz and the flicker was very deep (all on to all off). This gave me tremendous eyestrain in a few minutes, presumably because my irises were expanding and contracting very rapidly in response to the flicker. I gather that most people can't see this and have no issues with this bulb. I also had a (less severe) issue with a Philips LED bulb which didn't flicker but had a very harsh bluish light, so I'm at least somewhat sensitive to blue light too.

My interest in dithering arose from noticing that connecting a new Macbook to an old CCFL-backlit monitor which did not cause any issues at all when connected to an older Macbook resulted in severe eyestrain. Given that I'd eliminated the influence of LED backlights (there was none with the CCFL-backlit monitor) and PWM (there was only the softer PWM that CCFL backlights exhibit, which doesn't bother me), something else had to be responsible. That doesn't rule out the possibility that some people (presumably including you) have severe issues coming from other causes. We're all trying to understand all causes of eyestrain here, and so in addition to LED blue light sensitivity and PWM, we have to include dithering (or something that seems to be related to dithering) as one of the common causes.

Yet again I see that people are using the displays that cause problems and try to mitigate it with glasses, grayscaling or something else.

I just still would like to point out - try to eliminate all flickering/dithering displays for a couple of weeks, buy a display that is confirmed not to cause problems to a person sensitive to flicker. Then you might notice that no glasses or grayscaling or similar is needed.

When I use a flickering display, my eyes are also so sore that all kinds of lights seem to bother me (like lights in the gym) But that it not actually the gym lights, it's just the fact that I have my eyes open, which causes irritation when my eyes are sore from the flicker.

Just try the displays that I listed, you'll most likely come back reporting that the whole eye issue has resolved.

Yes, it took me too years to realize this and most people cannot just go and purchase $700 display to test. But as I understand, in many countries like US, stuff can be bought and then returned without any specific reason.

I'm now fully on top of what causes irritation and how to resolve it. It has been actually quite amazing last 6 months, as I've had zero irritation and red eyes, until last weekend, when I used the flickering iPad.

I've noticed that nowadays there are a lot of moisturizing eye drop commercials on TV. Also I've noticed that many people seem to have bloodshot eyes, more ofthen than say, 5 years ago.

My take on this is that people are using flickering LED displays that cause irrititatioin, but blame it on tirednes or the flu, or the wind or what ever, not realizing that it is actually the new LED TV or LED computer display or LED phone that is causing it. (LED is not bad as such, but the on/off cycle that is instant, makes the problem worse than CCFL)

My previous Samsung display was CCFL with PWM of 160 hz. That did cause irritation, but only if I was doing something like gaming 3 hours a night for 5 days in a row - then I just had to stop using a computer for a while.

It is all along been the flicker.

Does anyone understand this issue of 10hz PWM?

I take a shot at 1 second, even if it didn't make any sense, and to my utter suprise i found this:

low brightness

http://imageshack.us/a/img43/6748/rt7k.jpg

http://imageshack.us/a/img843/1034/48j8.jpg

this not make any sense... i count 10 lines. This means PWM of 10hz?????

This is really weird... Shouldn't i notice on naked eye?

Then i tried full brightness:

http://imageshack.us/a/img209/5106/5epd.jpg

Am i doing something wrong? I think i must so.

Hi mvanier,

I could verify with the frame grabber that when using the proprietary nvidia drivers under Linux, you can control the GPU dithering (nvidia-settings).

However the eye strain is not gone when disabling it and my best theory now is that the dithering on the monitor side cannot be controlled, and in the end having or not having eye strain is a question of luck and it depends on dithering pattern and colour calibration on both GPU and monitor side.

By best guess right now is to use a Linux notebook with an nvidia GPU and disable the GPU dithering, although is also probably not ensured that the notebook panel is not doing some dithering on its own which cannot be controlled...

I'm also not aware of any stand-alone monitor which is not using dithering. Even if the panel is 8bit capable it is still using dithering to increase to 10bit (for precise color calibration).

Mvanier, please continue discussing dithering I was in no way being critical of your inputs on that subject. My main point is that there are a range of symptoms here starting with what sounds like normal dry eye fatigue, moving to a more moderate eye strain issue and ending with something severe like my migraines and disorientation. I believe we have nothing close to a controlled scientific experiment here and everyone is saying "This works for me so it should work for you" just a little too much.

It appears we do have some great research going on here with monitors, my post was more questioning why some of us cannot tolerate any form of LED light and have immediately severe symptoms and some of us are simply talking about an irritation of the eyes or moderate eyestrain.

If only you and I were in close proximity to each other, we could test your monitor settings on someone severe like myself and we could answer some of those questions. The most interesting thing that could come out of this forum would be a controlled experiment with 3-5 of us ranging in symptoms, we could find common ground and possibly common solutions that could at least mitigate symptoms for most if not all people here. I do not have the expertise or the money to start testing different technology....

Being that you seem to have different sensitivities than myself I have a couple of ideas and questions for you:

1: Are you sensitive at night to LED tail lights on cars?

2:When you say you get severe eyestrain from a device, does this include any other symptoms like headaches or is it just eye pain?

3: The older 60hz fluorescent lighting you spoke of that bothers you, could you please try the Provencia coating under these lights and let me know if it helps? I am very curious about this!

One closing thought I will leave you with: When my sensitivity started 3 years ago it was milder and I only seemed to have an issue with overhead fluorescent lighting. It was not until I was exposed to some very harsh very blue overhead LED lighting for a period of 2 weeks about 1 year ago this past September that I developed a hyper sensitivity to all LED lighting. This poses an interesting question, is it possible those lights did some kind of permanent damage to my already sensitive brain/eyes during those 2 weeks of migraine **** while I tried to keep my job? Also, will those like yourself get more sensitive as they get more exposure over time? I certainly do not wish my level of sensitivity on anyone, it is terrible however, are some people here headed down my road?

Jessiah