Growing numbers of people in their 20s and 30s are reporting vision trouble. The cause is spending too much time staring at small screens. Staring too much at tiny details in the confined space of a small screen results in a condition known as presbyopia, a term derived from Greek words meaning "old eye." The condition may soon need a new colloquial name, perhaps "smartphone eyes."
Eye clinics around Tokyo report an increase of young people suffering from such symptoms as difficulty focusing on nearby objects and switching focus on objects at different distances. A survey by the eyeglass industry found that the number of young people reporting such symptoms of presbyopia increased from 0.5 percent in 2012 to 6.7 percent in 2013.
Japanese smartphone ownership increased roughly from 40 percent to 60 percent during the same period. In a report from South Korea, people in their 30s with presbyopia more than doubled over the past five years, as smartphones, tablet and laptop computers, electronic books and car navigation systems proliferated, just as they have in Japan. Though an exact causal connection has not been proven, concentrating on a smartphone screen can cause the ciliary muscles that focus the crystalline lens to lose function.