"The studies show that kids who spend more time indoors rather than outdoors—in the sun, exercising, running around—have a much higher degree of myopia, or nearsightedness," said Dr. Robert Cykiert, a clinical associate professor of ophthalmology at NYU.
Cykiert has been practicing since the early 1980s. He has seen roughly a 10% increase in children 5 to early teens who need glasses or contacts for nearsightedness. About 35% of children in the U.S. are dealing with some form of nearsightedness, he said, and is much worse in parts of Asia.
There isn't a definitive cause for the increase but more screen time in front of phones and tablets at both home and school could play a factor.
Parents should be on the lookout for squinting, declining grades and difficulty playing sports, which could all be symptoms your child's eyesight has declined.