Straight talk
Blue light: what is actually known
What you might expect to hear
“Blue light from your screen damages your eyes, and this lens prevents it.”
What is actually true
There is no good evidence that light from screens damages the eye, and no good evidence that a blue-filtering lens reduces eye strain. We will sell you one if you want it. We will not sell it to you on that argument.
Why
The tiredness people feel at the end of a day on a screen is real, and it is well explained by things that are boring: a blink rate that falls by more than half when concentrating, a small uncorrected error held at one distance for hours, and a focusing effort nobody notices making. Trials of blue-filtering lenses against clear ones have not shown a consistent difference in symptoms. The evidence for an effect on sleep from evening screen use is better, and that is a different claim about a different thing.
What we do instead
The measures that help are dull and free: the screen further away and lower, a lens set for the distance you actually work at, a break where the eyes look at something across the room, and blinking. If you would still like the filter, it is on the coatings list at what it costs.
The other eight
Straight answers to the rest of what this site will not pretend.
The dull, free things that actually help
Distance, position and blinking cost nothing. See the coatings list if you would still like the filter.