Bad during the day
Too much time staring at screens = too much blue light. This causes eye strain, fatigue, headaches, dry eyes and blurry vision. Blue = boo.
Worse at night
Blue light makes your body clock go funny. It blocks melatonin – the thing that reminds your body when it’s time to go to sleep.
Light below 400nm known as high energy visible light (HEV) induces retinal damage and cell death.
Light between 400-450nm is responsible for glare caused by Glare caused by LCDs, mobile displays and LED lights. Melatonin suppression, increased alertness, increased heart-rate, etc.
Light between 470-500nm is known as “good” blue light useful for various treatments (sleep disorder, seasonal depression, etc.)