Blue light is referred to the high energy visible (HEV) wavelength from 400-500nm.
Light at night is bad for your health, and exposure to blue light emitted by electronics and energy-efficient lightbulbs may be especially so.
Until the advent of artificial lighting, the sun was the major source of lighting, and people spent their evenings in (relative) darkness. Now, in much of the world, evenings are illuminated, and we take our easy access to all those lumens pretty much for granted.
But we are paying a price for basking in all that light. At night, light throws the body's biological clock-the circadian rhythm-out of whack, sleep suffers worse. Research shows that it contributes to the causation of Cancer, Diabetes, Heart Disease, Obesity and Depression. read more: Harvard Health Letter
See additional scientific documentary video Blue Light Health Effects
This video is an excellent summary of the medical research which has culminated over the past 25 years from numerous American and Canadian research institutions. It is well worth watching!
High Blue Blocking Glasses (85% blocking or more) worn 2 or more hours at night prior to bed time will help you Sleep Better, boosting your immune system, lowering your risk for life threatening diseases listed above and provide better brain health. See documentary While You Were Sleeping (Note this video is Geo-Blocked for Canada only).
Moderate Blue Blocking Glasses (20-40% blue blocking) worn while watching TV, computer screens or smart phones and tablets will reduce eye strain and improve contrast.
High Blue Blocking Glasses, Everyone, to promote a healthy long life. For Moderate Blue Blocking Glasses everyone that is in front of digital devices for multiple hours on a daily basis. Kids even more, as they have developing eyes.