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Comment by acd | Hacker News Reader

Seems like most common backlight is WLED. WLED seems to use bluelight diodes and phosphor. "called ‘white’ LEDs they actually emit a blue light which passes through a yellow phosphor "

This does not sound that good in the light that Chemist recently discovered that blue light speeds up blindness. Hacker News, Phys.org. Maybe a reason why for example submarines uses red light at night.

"Chemists discover how blue light speeds blindness" https://phys.org/news/2018-08-chemists-blue.html https://news.ycombinator.com/item?id=17724995

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The red light on subs is there to make it easier on your eyes to adjust to the dark and help with your night vision for looking through the periscope at night.

The reason is your night vision relies on rhodopsin, a compound very sensitive to light but not red light. So red light will give you night vision using the cone cells instead of consuming the rhodopsin in the rods of your retina.

Which is the same reason why astronomers use red lights when using telescopes and most of astronomy related software have modes where the screen have a red filter all over it.

> This does not sound that good in the light that Chemist recently discovered that blue light speeds up blindness.

This is a nice example of Chinese whispers at work. No proof was presented that blue light speeds up blindness, and besides that the amount of blue light in normal sunlight pales in comparison with the output of your average monitor. Sunlight is about 1 KW/sq meter, an LCD display is a very small fraction of that (which is why most displays except for e-ink are impossible to read in full sunlight).

It is not blue light but blue LCD. They triggers reactions in retinal molecules that destroy photosensors in the eye.

Surely the light from the sun is a much more damaging? Not to mention computer screens have existed for decades in some form now. I understand the connection with sleep, but Im not sure how much it really damages the eyes compared to other light sources.

Or course sun'rays are damaging, and it is why sunglasses exist. But if you are in front of a computer screen for 7/8 hours a day, you are exposed to blue LEDs which, unlike green and red LEDs are also damging for the eyes.

the amount of blue light in normal sunlight pales in comparison with the output of your average monitor.

Did you mean to write that the other way around?

Yep. Thank you!

the amount of blue light you get from a monitor pales in comparison to other sources of light, as discussed on HN last week.

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