Also know as "HEV" High Energy Visible Light. The largest source of blue light is sunlight. In addition, there are many other sources:
CFL (compact flourescent light) blulbs
Flat screen LED Televisions
Computer monitors, smart phones, and tablet screens
Blue light exposure you receive from screens is small compared to the amount of exposure from the sun. And yet, there is concern over the long-term effects of screen exposure because of the close proximity of the screens and the length of time spent looking at them.
According to a recent NEI-funded study, children's eyes absorb more blue light than adults from digital device screens. -Preventblindness.org
How to Reduce Exposure
Technological advances in the optical industry allow us to reduce exposure to blue light with a HEV filter added to anti-reflective coatings. This combination helps to reduce blue light as well as UV rays and artificial glare all in one coating!
Available for prescription and non-prescription lenses.