Blue light
Avoid blue light from artificial light sources and monitors as much as possible.
- Blue light is a contributing factor in myopia (near-sightedness) and macular degeneration (vision loss).
- Blue light can cause eye strain and headaches.
- High-energy blue light and lack of sunlight likely causes free iron to accumulate in and around your eyes, which is very bad. See: Iron Homeostasis and Eye Disease.
- Exposure to blue light at night inhibits melatonin production which disrupts your circadian rhythm and poor sleep, which leads to a number of health problems.
- There are likely many other negative effects of blue light that I don't feel confident mentioning here.
Avoid the damage caused by blue light by installing a blue light filter on your computer and phone (such as f.lux), avoiding screens as much as possible, and getting plenty of sunlight.
Research
There's a lot of research on blue light and eye damage, check it out for yourself. Here are some articles: