This is why looking at screens is bad for your eyes

Studies dating back to the early 1990s have looked at the effect that prolonged screen use has on our lives and mental health.

Everything from depression, breakdown in relationships, reduced work performance, failing academic grades, and degrading eyesight have been linked to an increase in screen time watching TV, using computers, looking at smartphones and, in particular, using the internet and social media.

However, research is unclear as to what causes what. For example, people who are feeling down may be likely to spend more time watching Netflix, rather than the latter causing the former.

When it comes to our eye health, spending more time looking at screens inevitably means spending less time out in the great outdoors. And the less time we spend outdoors and in natural light, the worse it can be for our eyes and vision.

There is a lot of science linking increased screen time with visual side effects.

The Myopia Epidemic

Pretty much everywhere you look around the world, screen time is increasing. Research from 2008 in the UK showed that adults spend an average of six hours looking at screens each day, and that was only considering computers, tablets, and phones.

We’re also seeing a global rise in cases of myopia or shortsightedness. It’s so rampant it is being called a global epidemic. A prime example being Asian countries where myopia affects eighty to ninety percent of all high school graduates.

The more time spent looking at objects less than arms-distance away from your eyes the more your brain begins to adapt.

Eyes are still developing until around the age of 16. Children are much more at risk of developing myopia than adults. Staring at screens and being indoors for extended periods of time can mean a child’s eyeballs can become slightly elongated, causing the lens to focus light from far objects slightly in front of the retina rather than directly on it.

As sight is crucial in a child’s development and how they understand and perceive the world, even the slightest of changes in vision can have far-reaching effects on their future lives.

Thankfully, just as myopia can worsen due to lifestyle and the conditions of the environment, it can also be at least somewhat managed or reduced by changing lifestyle and conditions.

Go outside and play

Recent research from Nature shows that the only environmental factor that seems to prevent myopia is spending more time outdoors. Previously, researchers believed that the recent degradation in vision was due to blinking less and the eyes constantly having to refocus when looking at digital screens. And there’s some truth to this, but some studies are starting to draw new links with the outdoors.

For instance, one study attempted to compare the eye health of children who spent their time looking at screens and those who did physical activity instead. Interestingly, it wasn’t the physical activity that made the difference, but rather if the children were indoors or outdoors—no matter if they were playing sports, having a picnic, or simply playing on the beach.

These findings support the idea that light has some protective properties for vision. As well as greater viewing distances and being able to see as far as the horizon, some research demonstrates how exposure to moderate levels of natural light every day can help safeguard vision and slow the progression of myopia.

Ian Morgan, a myopia researcher at the Australian National University in Canberra estimates that children need to spend around three hours per day under light levels of at least 10,000 lux to be protected against myopia. This is about the same as what you would get from sitting under the shade of a tree, while wearing sunglasses, on a bright summer day. An overcast day can provide less than 10,000 lux and a well-lit classroom or office is usually around 500 lux.

Three or more hours a day spent outdoors may still be the norm in some parts of the world, but for many of us who spend more and more of our time in front of screens—especially in Europe, the US, and East Asia—the time is becoming less and less.

More than a century ago, in 1904, the renowned British eye surgeon Henry Edward Juler hinted to what researchers are now just discovering. In A Handbook of Ophthalmic Science and Practice, he wrote that when “myopia had become stationary, change of air—a sea voyage if possible—should be prescribed”.

Maybe you don’t need to go on a sea voyage to protect your vision. But making sure you spend a few hours a day outdoors, where there is lots of natural light and fresh, open-air, may just keep your eyes healthy and help you avoid those readers for a little while longer.