"There are a number of factors involved in the increase of myopia, but I have no doubt that changes in lifestyle over the past several decades that include more time spent indoors and the early use of handheld computers play a big role," said Dr. Maria Liu, head of the new Myopia Control Clinic at UC Berkeley’s School of Optometry.

"The problem with smartphones and iPads is that kids often hold them closer to their eyes than they would a book, and they can become totally absorbed for hours at a time," she said.  "The working distance for handheld devices is much closer than it is for laptops and TV."
 

Focusing for hours on near objects, such as a cellphone, reduces the eye's ability to focus on things in the distance, which is myopia. Children are especially vulnerable because their eyes are still developing.
 

The problem reaches beyond the need for glasses or contacts. Eyeballs with myopia are more egg-shaped than eyes with perfect vision, and they are linked with a higher risk for eye diseases, including glaucoma, cataracts, and retinal detachment.
 

"The earlier the myopia starts, the longer the disorder has to develop into something more severe," Liu said. "It’s relatively rare, but in pathological myopia, the excessive elongation of the eyeball dramatically increases the risk for retinal detachment, growth of abnormal blood vessels and other complications, which can lead to irreversible vision loss." 
 

To reduce your risk of developing myopia, clinicians suggest taking frequent 10-minute breaks from computer screens and other small electronics, and spending time outdoors, absorbing sunlight and focusing on distant objects.