New answers tagged


The eyes cannot focus on something a few centimeters away. The average maximum distance where the eye can still focus is 14 Diopters in young people (Duane, 1922) (approximately 7 cm in 8-year olds). The distance to the eyes of the display in a head-mounted display (HMD) is often less than this and hence the eyes cannot possibly focus on this. Instead, with ...


This is an interesting phenomenon which I have been aware of for several years, but I haven't yet come across any official description of it or explanation for it. Nonetheless, the phenomenon is easy to explain. It is a result of light adaptation in your retina responding to different levels of light being received by each eye. Background The level of ...


I do know that the TED Ed episode linked (at 3:50) actually says that 500 million people have myopia or hyperopia, which is 1000 times what the question says, and which seems more reasonable for a world of 7.4 billion people (skewed towards the young).

Top 50 recent answers are included