What is Blue Light and is it the Same as UV Light?
Updated: Nov 24, 2019
It's safe to say that majority of us cannot live without our digital devices. With that in mind, blue light exposure is increasingly becoming a problem . Many don't understand what blue light is or believe that blue light is the same as UV light. Even though protecting your eyes from blue light is just as important as protecting your eyes from UV, each affects the eye differently.
Here are some facts about blue light and how it is different from UV light.
Sunlight contains UV and blue light
UV light is part of the non-visible light spectrum (UVA=315nm-380nm, UVB=280nm-315nm, and UVC=100nm-280nm)
UV light exposure affects the front of the eye most, increasing the risk of cataracts, photokeratitis (sunburn to the eyes), pinguecula, and pterygium.
Blue light is part of the visible light spectrum (400nm-495nm)
Blue light exposure affects the back of the eye most by changing retinal cell composition and potentially damaging the retina.
It's believed that the 415nm to 455nm band of blue light is most harmful to the back of the eye.
But not all blue light is bad...
Blue light of wavelengths around 470nm is effective against seasonal affective disorder (SAD)
Research has also shown that blue light around 488nm helps regulate circadian rhythms (our body’s natural sleep and wake cycles).
So how do we protect ourselves from the bad blue light and still allow the helpful blue light through?
Newer generation blue blocker lenses are now better and more aesthetically pleasing:
They selectively cut out the harmful blue light while still allowing the beneficial blue light to pass through.
UV wavelengths are also filtered out in the newer blue blocker lenses.
A strong yellow residual colour was seen in older generation lenses and many lens companies tried to counteract that by applying a strong blue/purple anti-reflective coating. Many patients did not like the look and therefore opted out of getting the blue blocker. This is no longer an issue with the newer blue blockers because they look just like regular prescription lenses.
So who’s going to need the most protection?
Frequent users of LED computer monitors, tablets, or smart phones.
Those who have a family history of age-related macular degeneration or are currently diagnosed with the condition.
Those who frequent tanning salons or enjoy tanning outside.
Ask your eye care professional if blue blocker lenses are recommended for your next pair of glasses.