Eye strain from LED backlighting in MacBook Pro

I just wanna say thanks to everyone who posts Information In here. I check this everyday to see If I can learn something new. When It comes to using my computer It seems the only relief from flickering I can get

Is when It's hooked up to my plasma tv. Is that because of the 600hz? I'm not really sure myself but I don't notice any flickering Issues when using It. I use a Samsung plamsma that I paid 399 for 3 years ago. I was wondering If I bought a new plasma T.V. would I be able to use that one with no Issues? I'm just wondering have they changed the technology In the Plasma T.V.'s? Are they loaded up with fluorescent and LED bulbs?

I currently use a Pioneer Kuro Plasma monitor for computer use, it is 7 year old tech. at this point. Part of why a plasma works has to do with the millions of individual noble gas cells containing the three primary colors of red, blue and green. Phosphor coatings are also used to make accurate color behind the gas cells. The technology is difficult to explain but the gasses work similar to fluorescent lighting by reacting to electricity to create light. Plasma's provide a very accurate color spectrum however they use much more energy for the same reason an incandescent light bulb does, higher heat to work.

In my personal experience something has been done to newer plasma monitors that has made them much worse for me to view than my 7 year old Pioneer which is the only monitor I have left I can use comfortably. So I would say you are at risk trying the newer Plasma's however often places like best buy accept them as returns within 15 days for a full refund so no harm in trying them out. I would try Panasonic or Pioneer if you can find one that is affordable, I do not think they make anything lower priced any longer....Were talking $5000 plus for Pioneer elite models if those are even still available.

Hope this is helpful,

Jesse

Jessiah1, i want to suggest you one thing (probably you already have tried it). Stop using the plasma for one week, there is a small probability (for some unknown reasons) of that screen to give you eye sensitive to other screen thecnology. Then try again a flicker free led monitor.

If you dont understand science, try harder, study more about it. It's not my science by the way, it's everybody science...

http://www.displaymate.com/Spectra_QD.html

Can you see those graphics? For instance the ipad blue line. That's the spectrum for white light. The sum of that spectrum gives white light. As you can see from the ipad graphic, the blue narrow part of the spectrum (400-500nm) has twice the intensity of energy of red part of spectrum and also almost double the green part. The red and green cover more then the blue which really narrow, but the blue is much more intense. That graphic is white light that the ipad has. This white light is not uniform as opposed to the sun which is almost flat... Almost same intensity for all parts of spectrum.

It's not saying that the blue light of the led it's not the same of sun, but that has nothing to do with what i am saying. Not all whites 'are the same'... The way you combine all colors, spectrum variations, you get different whites...

If you say so. Good luck with your problem.

tfouto said:

"It's totally diferent, the spectrum of light of a clear sky and a led screen.

Clear light it's a flat spectrum. All the cones of the eye are receiving the same amounts of light. The processing of color in the brain is even.

On a led screen, the light is basically almost blue part of the spectrum at a high energy. The green and red are much lower. The blue cones are the most stimulated. And the problem is that the eye has much less blue cones than green or red. Much, much less. I suppose the blue cones are much more sensitive, or the brain processing the blue is more efective. Maybe the processing of light in brain with such an uneven spectrum of light is problematic for some.

The problem is just not the blue light, it's the totally uneven distribution of light. That's the difference between a clear light and a LED screen. It's the relationship between the amount of total light received by all cones and the blue ones... A world of difference..."

I have to agree with peter_watt here about the uneven spectrum distribution "problem". He's writing from an unbiased point of view. Uneven distribution of light frequencies is called colour. If uneven color distribution was a problem, you couldn't stand looking at red, green, blue or any colors individually. All you would be able to tolerate would be perfect white full-spectrum light, which also contains blue. If your screen doesn't even come close to looking blue, this means it has an extremely lower percentage of blue in its spectrum then the blue sky, which is extremely blue and extremely bright.

I can see the problem of the blue light being uneven. Red and Green can aloso be uneven,. But if Blue is the problem, coudl blue filtering glasses with F.lux and maybe throwing sunglasses on top, create a situation where the blue spike is completely removed and all other clours are also move even, as the whole level of light is so much lower that it is hard to say diffrentiate it from, say looking at a paintin that is dimly lit.

That way one coul be sure that if blue is the problem, then there is hope that when manufacturers make a solution that makes the light spectrum more even, also your eye irritation disappears.

I personally tried to use the flickering displays with blue blocking glassses and f-lux installed and set to the maximum yellowness, but that made absolutely no difference. I've also tried wiht with dark sunglasses. Only removing the flicker, removes my eye irritation.

mojarvinen,

Your problem dont have to do with blue-light, so using blue-blockers dont to a thing...

Flicker/dithering is the main cause.

Dovez,

I am tired of repeating myself, really. If you dont grasp the concept, i cant repeat myself to death.

It has to do with mixing of coloures. Sun white, is even... The brain processes normally the white. On those Led screens, dont... The brain is processing whites and mixtures of colours on a non-natural way, which is used for millions of years. There are physicians who said this.

Why kindle paperwhite front-light causes me hard pain at full brightness? Dithering, flicker? Of course not...

And why flux, solves the problem to me on led displays?

It's not blue alone. The problem here is the brain is processing the mixture of colours especially white, with an uneven spectrum intensity of light. It's a theory, i might be wrong, i might be right, who knows. But it's not blue light alone...

Let's say a person has a problem with a monitor. Irritated eyes are the problem. Just think about if this explanation makes sense:

Let's imagine your light stress tolerance level is at 50 (which would mean you can tolerate all light stress up to 50 points). Let's imagine 45 points of stress is caused by invisible flicker and 10 is caused by a bit excessive presense of blue light in the spectrum. together we have 55 and the person gets irritated eyes because of too much light stress. Imagine the person uses flux and reduces 70-90% of blue. The light stress level is under 50 again and the person says he has no problem. He then claims blue light was the problem. But what if the flicker was removed? I think the blue dominance wouldn't play a role.

Let's imagine you have a different tolerance level. 30, for example. You still have 45 poins of flicker light stress and 10 of blue stress. Here removing blue doesn't make a difference, but removing flicker makes a diffeerence for everyone.

If this is correct, then removing all kinds of flicker would serve as a universal solution and removing blue would be only helpful for some.

tfouto wrote:

Why kindle paperwhite front-light causes me hard pain at full brightness? Dithering, flicker? Of course not...

Why do you keep giving special importance to it being on full brightness? Do you think it doesn't flicker at full brightness? Have you measured it with a reliable instrument? Please repeat it if you have mentioned it here before.

tfouto wrote:

The problem here is the brain is processing the mixture of colours especially white, with an uneven spectrum intensity of light. It's a theory, i might be wrong, i might be right, who knows. But it's not blue light alone...

Don't you think using flux creates an unnatural uneven spectrum of light? I mean how is it natural when everything is red?

I will.

But PWM is no problem to me. I have 2 monitors with pwm, and dont have any trouble with that...

soundstar3

"Jessiah1, i want to suggest you one thing (probably you already have tried it). Stop using the plasma for one week, there is a small probability (for some unknown reasons) of that screen to give you eye sensitive to other screen technology. Then try a flicker free led monitor."

Interesting, I have never heard of this theory, can you tell me more about where it originated? As for testing it I certainly would not need to as I have spent weeks away from this monitor with no effect to my other sensitivities.

Based on the back and forth I see from last night I feel like both sides of the argument have interesting points and no one is completely incorrect necessarily. I say this because no one here is a physicist and therefore theory's are just that and nothing more, good discussion though🙂Allow me to add my own, haha!

The sun is a more even spectrum of light than any other source, even incandescent light bulbs, it also has the highest amount of blue light however it travels through many filters before it reaches our eye's.

Other sources of light like LED lighting are not filtered the same way and in addition to this they can deliver light in broken waves, flicker of light typed out would look something like this: - - - - - - - - - - -

So if you imagine a light source with uneven light spectrum that our eye's are not accustomed to viewing being delivered with flicker you have the worst possible case scenario, thus it bothers everyone. If removing one aspect of this scenario helps you it does not mean the other is simply tolerable for you by default, it means you improved the delivery of light to your eye's in a direction that makes it tolerable.

I think Peter has some experience with light that helps provide some educated feedback on this subject, otherwise I cannot tell who else here has an educational background in the Physics of light? I will be back here with more factual data when I have taken this further with some PHD's and hopefully the Boston Photonics lab. We all need some more scientific explanation in order to move our theories forward from here IMO.

Respectfully,

Jesse

This theory came from my own battle with screens for more than 5 months. My next test will be with a rubylith film filter that is usually used by astronomers. Most astronomical programs have a "red light" or "night vision mode". The screen will lose image quality, but im just looking for a comfortable way to use a screen.

There is other thing i would like to test, but couldn't find a way to do it. With flux it is possible to change the color temperature during a 24h period, what im looking for is a program that can change color temperature during 1 minute period, so it goes to maximum and minimum in each minute. There is a small probability of this to work for some persons. Why? Because when many persons change color temperature (or monitor or operation system) the eyes feel better for some time (minutes/hours/days). I think the eyes are more sensitive using same color temperature all the time, so if it changes every 1 minute (it could be more), the eyes will not feel saturate, and maybe for some it will solve the eye strain. Would like to find a way to change flux code, for a customizable perido (less than 24h).

Hope it helps and sorry about my poor english.

Edit: It's possible to test this idea without a program. I will set an alarm for every 3 minutes where i will change manually color temperature with flux. I will set an interval from 3500k to 6500k, and every 3m will increase/decrease 300k. For some persons flux work and i think if it goes to maximum and minimum more times a day it will also work with more persons.

Very interesting test, our natural lighting changes during the day constantly, I am curious how this test turns out. Being that F.Lux only helps me in a minor way I do not think it will solve my issues but still an interesting idea.

Jesse