Q: Eye strain from LED backlighting in MacBook Pro

Thanks Tfouto, great find and read.

Tight Eye: I will give you my personal opinion on your contrast theories. Contrast is similar to brightness and makes your screen brighter in it's own way. I know we have all gone back and forth on flicker, dithering and other possible contributors however if you think about it most likely everyone here is sensitive to both flicker and spectrum. If the screen is using an LED back light with strong blue light there is a good chance raising brightness or contrast is going to exacerbate your issues, especially in those monitors that have any "Shimmering" or flicker effects of any kind because they are pulsing these harmful light waves at you like stabbing a knife into your eye and then removing it only briefly causing your eyes to constantly constrict and never really relax.

The basic point I am trying to make here is there is a level of blue light in LED monitors that is harmful to our eyes, articles have been written on the scientific findings of this as a fact. No monitor company is reporting any measurements of blue light waves on their products either so we really do not know how bad it is. So, if we are even more sensitive to it than the majority of the population then anything that magnifies it's effects are going to make it worse. Contrast and brightness are not the problem, did you ever have any issues with your older Non-LED technology and brightness or contrast levels? The very article above about QLED's is evidence of the industry trying to correct this color imbalance because they know there is an issue!

These are my opinions, I share them to help the discussion so if you do not agree please do not be offended and continue discussing.

Jesse

Jessiah1

I share your view about the blue-light unbalance as the main cause.

About measuring the blue light waves, unfortunely it's very expensive to buy a device that measures spectrum. There are affordable devices to measure white balance and gama, but full spectrum devices are really expensive.

Let's hope more and more companies and Apple of course, will adopt QDED's or similar technology in

future.

Agreed, I have this feeling the spectrum of Blue light in many of our devices is so bad we really do not even want to know how bad it is, possibly even worse than staring at the sun for all we know. They are doing thing's to fix it and there are rumors of companies being held accountable to lighting requirements. I have read and heard verbally more than once that companies are going to have to start adding blue light filtration to their lighting, mainly industrial and residential LED lighting. I believe there is going to be a correction of this issue with technology advances however it could take decades to fix completely at this point.

Several medical professionals I have spoken with and my contact at Crizal have spoken with have stated we will have a new generation of vision problems 20 years from now because of the wavelengths of light our devices are using and I quote "Humans are not supposed to look directly at light, they are supposed to see WITH light". A major problem when that light is in the unhealthily spectrum for our eye's, were all in denial because we want to keep using (And keep letting our children use!) our Ipads and other devices.

Boo I say, but what can we do except wait?

Jesse

On another note, check out these fantastic new energy efficient Edison bulbs!!! No mercury and a simple very recyclable light bulb that uses similar energy to a CFL, yay Phillips I knew you could do it!

That is an incandescent halogen bulb in an opal outer bulb. No relation to CFL.

Jessiah1

There is nothing worst then staring directly at the sun. The sun is so bright it will blind you literally in minutes. Even if the quality of light itself might be 'good'.

Yes human eyes are not supposed to look directly at light.

I use those halogen bulbs. They are similar to old incadescent, except they use halogen, and have better efficiency because of that. Nothing is better to my eyes then this kind of light.

@Jessiah: No problem, didn't get that offending, I'm just engaged to find a solution, too.

As for the blue light I just can say that it could be a problem and we probably will never know until someone can measure the spectrum. As for myself I can say that I find blue tints on screen in terms of colour (I know spectrum is different) more pleasing than most IPS displays being more warm, red and yellow. Hope you know what I mean.

On the other hand I doubt, that the devices I can work comfortable with are all exhibiting less blue light.

The only fact which is the same on these machines for me is low contrast or lower than average. It's imo relative brightness which is bothering, which makes sense to me when I compare my view on an iMac to what I see when I read a book. The book just looks flat, there is basically nearly no contrast at all and it's super pleasing.

I think I'm going to give you guys my opinion about the VAIOs shortly. Actually I'm sitting in front of an Haswell iMac 27 which first gave me a nice headache for 3 days, now I'm on day 5, it is barely tolerable for me now cause the headaches are almost gone. Tiredness and flickering vision persist though. This flicker in the eyes is the most bothering to me. It feels like pulsating content is hitting my eyes and nothing's standing still.

http://en.wikipedia.org/wiki/Cone_cell

"Cone cells, or cones, are one of the two types of photoreceptor cells that are in the retina of the eye which are responsible for color vision as well as eye color sensitivity;

Cones are normally one of the three types, each with different pigment, namely: S-cones, M-cones and L-cones. Each cone is therefore sensitive to visible wavelengths of light that correspond to long-wavelength, medium-wavelength and short-wavelength light.

Humans normally have three kinds of cones. The first responds the most to light of long wavelengths, peaking at a reddish colour; this type is sometimes designated L for long. The second type responds the most to light of medium-wavelength, peaking at a green colour, and is abbreviated M for medium. The third type responds the most to short-wavelength light, of a bluish colour, and is designated S for short. The three types have peak wavelengths near 564–580 nm, 534–545 nm, and 420–440 nm, respectively, depending on the individual.[10][11] The difference in the signals received from the three cone types allows the brain to perceive all possible colours, through the opponent process of colour vision. (Rod cells have a peak sensitivity at 498 nm, roughly halfway between the peak sensitivities of the S and M cones.)

The results illustrate that S cones are randomly placed and appear much less frequently than the M and L cones. The ratio of M and L cones varies greatly among different people with regular vision (e.g. values of 75.8% L with 20.0% M versus 50.6% L with 44.2% M in two male subjects).[15]"

My words now...

We all know that those LED's screen have a peak blue-light energy compared to Green and Red.

http://dotcolordotcom.files.wordpress.com/2012/03/white-ipad-3-color-spectrum-ch arts.png

And we humans have much less blue cones, then green and Red. No wonder that our blue cones get stressed. Our brain, when processing/decoding colors/signals from the cones get confused/stressed which such unnatural and unbalanced spectrum of light. The cones we have in much less quantity are the ones that are the most used. Maybe we suffers have yet less blue cones then majority of population, or a different ratio of L, M and S cones.

tight_eye, does using flux help you?

P.S.- Maybe we can buy a spectrum measure device among all. Or use it for 15 days, then send it back...

Peter, I know it is not related to a CFL, I was stating it's energy use is probably close to that of a CFL and it has no mercury or other hazardous wastes! Much better carbon foot print and healthy light because it is essentially an incandescent light.

tfouto:

"There is nothing worst then staring directly at the sun. The sun is so bright it will blind you literally in minutes. Even if the quality of light itself might be 'good'."

Agreed, I was being dramatic. In fact the sun has the highest level of blue light however we are not supposed to look directly at it but to see with it. It would damage our vision if we did so why are we looking directly at high level blue light in LED monitors? The sun also has extremely high levels of red which offset the blue just like the QLED displays, very interesting:) Im no scientist  so my statements are from my un-educated reading so forgive if I am not 100% correct on something.

Jesse

FLUX didn't help me. Not better, not worse, nothing.

tfouto, Your explanation of the cones is accurate to what my conversations with my contact at Crizal have been about. They made the Provencia coating specifically to block the blue light that is harmful (There is good and bad blue light, good blue light helps keep are sleep cycles correct for example) Within a certain Nm measurement some blue light is simply harmful to our eyes, this is supported by science. The Provencia coating blocks only 20% of this wavelength, my hope is a coating that blocks a higher% of this harmful blue light will help with high blue LED's further.

The effectiveness of Provencia while minor with LED's is measurable for me, for example: I cannot use my iphone 4 at all without my glasses and with my glasses I can use it for 5-10 minutes at times with no ill effects. With fluorescent lighting the effects are much greater, I can tolerate 2-4 hours with my coated glasses. I know some people here do not have an issue with fluorescent lighting so there are obviously some differences among us.

They are of course looking into a stronger coating but the problem with a stronger coating is aesthetically it is very obviously there, almost like a brown/purple mirror tint. Since the market in general is not as light sensitive as we are there is not enough of a reason for people to start wearing aesthetically ugly coatings on their glasses so I do not know if they will have anything available anytime soon.

So, with the industry evolving their technology away from overly blue screens and companies who make anti-glare coatings to block blue light I think we are on the right track for a better future one way or another, just a matter of time. Nothing will beat the incandescent light of course in quality, fire is how humans have evolved to see at night and it will long be the best light source.

When we create un-natural light we create eye sight problem's, this should not be surprising, whenever the human race modifies nature there are consequences. I have one further input to tie in flicker, I don't remember if I have stated this here but my pellet stove fireplace flickers due to the exhaust air escaping the stove. The flicker of the fire is faster than normal because of this vacuum and it gives me headaches just like monitors only not as strong. Normal fire is even better for me, it flickers less unless the wind is really strong say in a camp fire. Fire being full spectrum light like the sun and it bothers me when it flickers? We are obviously all sensitive to flicker as well as blue light, so it makes perfect sense that previous generations of monitors that were lower in blue peaks were more tolerable even if they flickered because the light was closer to full spectrum. The more white/blue peak means a much stronger effect on our eyes if there is any image stability issues like flicker.

Thank you for the post on our Retina cones, it illustrates my point about blue light very clearly. Sorry for the long post everyone and thank you for reading if you did!

Jesse

tfouto and tight eye: What does Flux really do? How much of an effect can it really have if the light source is still the same? Does Flux simply reduce contrast or brightness, how does it reduce the blue light?

Jesse

Tight eye, I think we are in agreement here. Contrast or brightness will definitely increase your issue, the brighter the light the worse it is going to be, no doubt about that. In some cases I think it helps slightly if brightness is 100% because the screen may stop flickering on PWM monitors however the brightness level probably offsets the positive gains of losing flicker a great deal by increasing the brightness of the blue light too much! I'm not sure it matters what the appearance of the display color is, the back light is still the same even if the screen appears to be red/yellow. In fact the blue might be worse under those settings to create that appearance, who knows without a measurement.

"@Jessiah: No problem, didn't get that offending, I'm just engaged to find a solution, too.

As for the blue light I just can say that it could be a problem and we probably will never know until someone can measure the spectrum. As for myself I can say that I find blue tints on screen in terms of colour (I know spectrum is different) more pleasing than most IPS displays being more warm, red and yellow. Hope you know what I mean.

On the other hand I doubt, that the devices I can work comfortable with are all exhibiting less blue light.

The only fact which is the same on these machines for me is low contrast or lower than average. It's imo relative brightness which is bothering, which makes sense to me when I compare my view on an iMac to what I see when I read a book. The book just looks flat, there is basically nearly no contrast at all and it's super pleasing.

I think I'm going to give you guys my opinion about the VAIOs shortly. Actually I'm sitting in front of an Haswell iMac 27 which first gave me a nice headache for 3 days, now I'm on day 5, it is barely tolerable for me now cause the headaches are almost gone. Tiredness and flickering vision persist though. This flicker in the eyes is the most bothering to me. It feels like pulsating content is hitting my eyes and nothing's standing still."

Tight Eye, the image instability is something I see just like you, we share that. A lot of these new monitors appear to be "moving" when I look at them, I will say I was pleased to not see this for the first time when viewing the sony vaio. I wonder exactly what the difference is that makes the image appear more stable?

"This flicker in the eyes is the most bothering to me. It feels like pulsating content is hitting my eyes and nothing's standing still."