Abraham Lincoln studied law by the light of the fireplace, legend has it. If he had gone to law school today, he might have wound up being severely near-sighted, according to a University of California professor.
"We see that one of the consequences of going to law school is that students may become more nearsighted. Students graduate with a law degree and greater myopia than they had when they first enrolled. It’s a casualty of the profession, because they spend most of their waking hours reading, often on a screen," said Robert DiMartino, professor of Clinical Optometry and Vision Science at UC-Berkeley.
"Sixty years ago, only 10 to 20 percent of the Chinese population was near-sighted. Today 90 percent of children and young adults have myopia, according to research," DiMartino said. "And now we’re seeing the same trend in the West."
DiMartino said that not only are more people becoming nearsighted but the degree of nearsightedness is becoming more extreme -- an increase both in the prevalence and the magnitude of myopia.
Risk of other problems
Even worse, near-sightedness puts you at increased risk of at least two other eye conditions: glaucoma and retinal detachment, DiMartino said in an interview published by BerkleyWellness.com.
"People become nearsighted because their eyeball has grown longer, so light entering the eye can’t focus directly on the retina as it does with a normal shaped eye. When the eye elongates, it also stretches the retina, which increases the risk of retinal detachment. Elongation also causes subtle changes to the structure of the eye, increasing the danger of glaucoma," he said.
DiMartino said the exact cause is open to debate. Some blame the blue light emitted by laptop and mobile device screens.
"But the bigger problem, I think, is that with the advent of mobile devices, we spend so much more time focusing up close, and so much less time outside, focusing on distant objects. Our eyes need a balance between focusing up close and focusing at a distance in order to remain healthy," he said.
While it's hard to say just how much screentime is harmful, DiMartino said it's obvious that it's " important to seek a balance where we're doing distant tasks as well as near tasks."
Children, especially, should be encouraged to spend more time on activities that use distance focus, like sports, hiking, and spending time outside.