How to test blue light glasses

Using a spectrometer to evaluate blue light filter glasses is the most accurate method.

This is laboratory equipment that separates light rays into its many wavelengths. The Blue Light Blocking glasses’ lens is inserted into the instrument, and a detector detects whether part of a given wavelength is passing through or being stopped by it.

The results are exceedingly accurate since this is highly qualified lab equipment, and it is the gold standard for evaluating Blue Light glasses. Nevertheless, the drawback is that it is a very pricey tool which is not available to most people. This is not accessible at an optics store or at your physician’s office, and it is only available in highly specialized optics labs.

By using two different spectrometers, our glasses have been proven to filter 99.9% of blue light between 380 and 500 nm making them protective eyewear.

A test that can give you a general idea on how your blue light glasses work is the RGB (Red green and blue) color wheel test.

In this exam, you use blue light glasses and examine the blue and black squares. If they both seem black, your glasses have fully blocked the blue light.


  • Examine the squares below. Accordingly, they are blue and black.
  • If your glasses totally filter out blue light, both squares will seem black or somewhat dark grey.
Black and blue squares

Ignore the blue light pen test; it is only for marketing purposes.

It produces violet light rather than blue.

How about red, yellow, and clear lenses?

The most harmful wavelengths for sleeping are below 500 nm, which is why we don’t use red lenses since blue light has a wavelength range of 380 to 500 nm. If you wish to filter more than 500nm with 99.9% efficiency, the lens must be darker and redder. There won’t be much, if any, benefit to your sleep, and everything will be excessively red and your eyes will have to strain themselves to see anything, which increases your chance of developing eyestrain.

Contrary to what the majority of clear and yellow lenses claim, they do not filter 99.9% of light. Clear lens block 30% of blue light, where as yellow block about 60% of blue light.

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