Important advice for people who work with computers & read lots of documents:
"Your eyes are the products of millions of years of evolution. Unfortunately, this means that they’re optimized for spotting prey across the savanna, not for peering at letters built up of little dots on tiny screens. In recent years, optometrists have come to recognize a complex of eye and vision problems they call Computer Vision Syndrome, or CVS for short.
"When you spend your day looking at computer screens (especially poorly-maintained screens, or the tiny ones on mobile devices), your eyes strain, you blink less, and your body gets generally unhappy. The result? Fatigue, headaches, blurry vision, dry eyes, neck and backaches, and even double vision."