Blue Light Blocking Glasses: How They Work and Why They Work

What a racket. Low density article that focuses more on selling the idea of spending hundreds of dollars on stylish glasses than it does science. “Colored lenses are new”. No they are not. You can get these for $5 at any gas station or convenience store. Absurd.

This looks rather like an advertisement with dodgy links to buy the product so I'm not sure I'd trust the "review".

The article itself is kind of trash, but there is some semi-decent science behind the idea.

https://www.healthline.com/nutrition/block-blue-light-to-sle...

Blue light disrupting sleep is definitely a real thing, and studies so far suggest that using glasses to counter the effect can work, though (as detailed in the PubMed article which the Healthline article laudably cites) those studies have so far been too small/weak to prove any such thing.

I got my computer glasses prescription in "Digital enhanced" format, for which I payed an extra steep price, and I felt that I've been oversold.

What that does is actually adding a subtle yellow tint to the glass and anti-reflection coating.

The single best eye wear-related decision this year - so good that I headed back and got myself a backup pair. My eyes are so much better rested after staring at a screen 8h+ a day, even if I used redshift to reduce the blue tint. Also I fall asleep so much quicker and I sleep better, and I credit the glasses for much of the improvement.

I have a cheap pair (not the affiliates linked in the blog), and find them useful.

Then again you can use apps like f.lux for free - although the reason I bought glasses was because I couldn't find a clear answer to whether or not software blocking was effective, or as effective as hardware (glasses).

There is some criticism in other comments here of the blog as an advert, but it seems like a useful overview to me, with affiliate links.

My son, just yesterday, asked to get some fancy gaming glasses. I've always assumed it was junk. However, the particular brand happened to have a credible review on YouTube by a presumably unrelated eye doctor who does a series on eye stuffs. In this brand's case, they have slight magnification and slight prism effect (like uncrossing your eyes) that places less strain on your eyes when being close to a screen. Those seemed like real benefits. I'm not sold on the blue light part aside from when it is time to get ready for bed. But the glasses came in on sale for like $15 with shipping, so we will find out if they are any good.

I've worn the Gunnars brand for... at least eight years. I don't wear them every day, but they help me with eye-strain and related headaches. I couldn't judge the effects on sleep as I have insomnia anyways.

I was looking for blue light blocking glasses online shipped to Europe at reasonable price but couldn't really find any, other than on aliexpress. Would be interesting to try.

A note: the computer glasses you may see advertised that are clear (or at most have a mild yellow tint to them) do almost nothing to help with melatonin suppression. Light-based melatonin suppression is largely mediated by light receptors on the retina called ipRGCs. They are the third class of photoreceptors, along with rods and cones. They respond in the very approximate range of 380nm (violet) to 600nm (yellow), though suppression is diminished as one strays further from the peak of ~475nm, tapering off to zero around the limits I have given. [1] So if you want lenses that actually work, expect very heavy color distortion.

This also applies to the fancier lenses on prescription glasses. If you are optically challenged like myself, and have bought glasses recently, you've probably been upsold to lenses that block short wavelength blue & near UV light. For example, Zenni's branding is BlokZ, which are apparently designed to to prevent "FryEye". There may be some benefit to blocking short wavelength blue (and there is obviously benefit to blocking UV), they will not help with sleep.

For the purpose of my sleep cycle, I prefer to use software filters (f.lux, etc.) rather than colored lenses. As long as the blue (and green, to a lesser extent) subpixels on my display aren't lit, it's just as effective. In fact it's a bit nicer, as it's possible to "redscale" the image based on luminosity rather than just not seeing blue any more. (I am not sure if f.lux is capable of this, as I do not use it.) To limit the effect of environmental lights, I use very warm LEDs in the evening and dim them down low as the night goes on. I'm tempted to mix in some red and orange ones right near bedtime to get an almost firelight effect.

Unrelated, but for general eye strain at the end of the day: get some reading glasses, even if you don't actually need them to read. They'll let your ciliary muscle relax by making your screen seem to be at optical infinity. If you already have glasses, just take your prescription and throw +2 or so SPH on there. (Or, if you don't mind being a bit of an annoyance, pop to the drug store and try on some pairs on your regular glasses until you find the right diopter. Or, even better, calculate it using the thin lens approximation.) You may want to add a prism if you're prone to being cross-eyed.

[1]: While not from a scientific publication, and obviously heavily smoothed, this graph gives an idea: https://www.rasc.ca/sites/default/files/Retina_Spectrum.jpg