My teacher told me that all myopia is genetic. is it? does playing computer or reading in short distance affect the refraction of light to our eyes?tq

Genetic + more: Genes definitely play a big part in determining who will become myopic. However, we have found that there are many environmental factors, as well. Recent research has found that people who spend more time indoors growing up VS outdoors tend to develop more myopia. Playing on computers is unlikely to affect a person's ultimate refraction, but reading at a too-short distance may affect it.