Your parents were right: Staring at a screen all day will ruin your eyes. The only thing they got wrong was the kind of screen. Light emitted by LED-illuminated screens, the kinds you find on smartphones, tablets, and computers, kill the cells in your retinas as you use them. New research found that, in rats, three-months’ worth of screen use led to a 23% increase in retina cell death.
The study arrayed regular consumer tablets around rat cages. The tablets where switched on for 16 continuous hours per day for three months, and then the retinal damage in the rats was compared to that of a control group that didn’t have to stare at the screens all day long. Finally, a third group was subjected to the same conditions, only with a filter over the screens to cut out certain wavelengths of light.
The study, from the University Complutense in Madrid, was commissioned by the company behind the filters, Reticare, so you should consider the study as a publicity exercise as much as science. However, previous studies have also shown that radiation can damage retinal cells, and that we spend a lot of time in front of screens. For instance, 18-year-olds spend around 7.5 hours looking at a screen each day.
Thanks to the ubiquity of screens, computer vision syndrome is suffered by between 64% to 90% of computer users, the symptoms of which include “eyestrain, headaches, ocular discomfort, dry eye, diplopia, and blurred vision.” Even without the problems of radiation, a screen forces you to focus close-up for long periods of time, which causes strain on your eyes.
In the Reticare test, one interesting result was that, thanks to the way light works, its effects grow exponentially as the source gets closer to the eyes. This, says the Reticare press release, leads to children getting bigger doses. “Due to their shorter arms, [children] are exposed to high energy light at a shorter distance than an adult who uses the same device.”
Whether or not we put any trust in the Reticare study results, then (and so far, I can’t find the paper published in any scientific journals–I received a copy of the report by email), the rest of the evidence shows that staring at a screen all day is bad for your eyes. The answer? Perhaps you could look into filtering the screen, although a better option might be to just spend less time in front of screens to begin with. Get your computer work done as fast as possible, and take regular breaks away from the screen instead of goofing off on Facebook every half hour. And the next time you’re on public transport, maybe consider looking out the window instead of looking at your phone.