Quote:
Originally Posted by viceant
Reduction to absurd is for maths issues and this is not maths. You're, also, making a straw man. Placebo effect is real and too much people thinks homeopathy works.
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The difference of backlit LCD and frontlit eink is not a placebo effect. The quality of the light is different. I am not saying one is inherently better or worse for your eye health. I am just saying there is a measurable difference. It also makes a big difference what light source you are using and how you go about bouncing the light off. A reflection does usually mean bouncing light off of a mirror like flat surface. That is not what is happening with eink. Ignoring glare for a second (every eink I have see does have glare, even if you usually have to go out of your way to see it), what makes eink visible is diffusion. That can come either from external light sources or a front light. Polarization matters as well. It is not the direction the light travels, but what direction it "swings" while it is going wherever it is headed. Reflection changes the polarization to be "sideways" from the angle of the mirror. Reflecting polarized or diffused light off a surface will result in polarized light which direction will depend on light source, position of mirror and position of the eye. Diffusion is viewer independent and not polarized, whether you use a polarized or non-polarized (diffuse) light source.
So far, so good? Now it gets more complicated. An backlit LCD panel is neither diffuse nor reflected. But it is still polarized through a set of polarization filters. The backlight itself is diffuse, similar to how a photographic softbox looks like. That diffuse light gets filtered to be polarized, this time around not through reflection, but by eliminating the majority of the light that swings in an undesired direction. Then it hits the liquid crystal layer that will turn the light depending on how much voltage is applied. Then it hits another pol filter that will let white light through the best and black the worst, depending on how far you twist the light. Then it hits a color filter in the case of a color LCD. No matter how you eluminate eink, the resulting light is always diffuse. More natural light, just like a traditional paper book looks.