This test works for clear daytime lenses and computer glasses. This is the simplest test you can do at home, but it doesn’t indicate how much blue light is being blocked (ideally, you want to block 30% of blue light).

The color warms up because there are special pigments in the lenses designed to absorb blue light passing through. If the lens is clear and the color of the background doesn’t warm up, it means there is only a basic anti-reflective coating that filters about 5 to 20% of blue light maximum.

On Apple devices, this setting is called night shift. On Android, it’s called blue light filter. Night mode settings essentially do the same work as blue light blocking glasses, but not all devices have the software to do this. There is a variety of free blue light blocking software available for computers and other devices that don’t have a built-in night mode.

If your lenses are filtering out blue light, the blue square should now look black or dark gray. If the blue square still looks blue, your lenses are not blocking enough blue light.

The blue portion of the chart or wheel should turn gray or black if your lenses are blocking blue light. The green portion should also darken. The darker the green portion, the better (especially for orange or red lenses designed for nighttime use).

Yellow evening or driving lenses should block about 65 to 70% of blue light. Orange and red nighttime lenses designed for sleep should block 95 to 100% of blue light. Spectrum reports are useful no matter the color of your lenses—clear, yellow, orange, or red.

Many manufacturers offer a trial period so you can test out the glasses and see if they work for you. Trials work for any lens color, but orange or red lenses will have a greater impact on sleep than clear ones. The effects are especially noticeable for “night owls” who go to bed later in the night. Blue light blockers don’t help with eye strain. They only support better sleep since blue light disturbs your circadian rhythm (your sense of when it’s time to go to bed). [8] X Trustworthy Source Cleveland Clinic Educational website from one of the world’s leading hospitals Go to source