Do blue light-blocking glasses really work?
To test the filter of blue light blocking glasses, it is good to remember what this blue light is. Light is a wave, and depending on the frequency of this wave, the human eye perceives this light in different colors. Light is perceived as blue when its frequency is between ~ 390 and ~ 500nm in the electromagnetic spectrum.

Contrary to popular belief, not all blue lights are bad. Only the lowest frequencies, from 390nm to 450nm, are harmful to the eyes. These frequencies are close to UV (Ultraviolet), and as you know, these waves are bad for the eyes and the skin. This is why you apply sunscreen to your skin and wear sunglasses.

It’s the same for blue light; to protect yourself, you need to wear glasses that block the lower frequencies of blue light. These glasses have lenses with a protective layer that filters out harmful frequencies in the light spectrum. This filter prevents bad blue light from entering your eyes.

Test your blue light blocking glasses
Do not wear your glasses on your nose;
If necessary, disable your software which filters blue light;
Look at the two-color bars. They must be different;
Put your anti-blue light glasses on your nose;
Compare the two-color bars. They should now be identical.
Don’t panic if the two-color bars are not quite similar; no telescope filters 100% of the entire blue light wavelength. What is important is that your glasses filter out bad blue light, which is harmful to your eyes and sleep. The more the colors are identical to the left of line 450, the more efficient your glasses.