Science

Photo: bmx22c

Get outside, for the sake of your eyes

By: Alex Truong

Have your parents ever yelled at you to “get o your phone”, “stop playing video games”, or some variation of the sort? With the ever-increasing presence of digital technology in our lives, there’s a good chance that they have, and probably followed with some vague warning about how you’re going to regret ignoring them in the future when your eyes go bad.

Unfortunately, your parents are somewhat right about that (as they usually are about most things). In fact, we’ve actually seen a drastic spike in nearsightedness, also known as myopia, during the pandemic. In a recent study of over 120 000 quarantined children, Chinese researchers found that the prevalence of myopia and other vision issues had nearly tripled compared to the rates of the past ve years. Many attribute this spike to an increase in screen time owing to the introduction of virtual learning, but some recent studies have suggested that the more important issue may be the side e ect to all the screen-watching we’ve been doing recently: a lack of time spent outdoors.

While a direct, causal relationship has yet to be found, researchers from the University of Cambridge concluded that, in children, “for each additional hour spent outdoors per week, the chance of myopia dropped by approximately two percent”. is 2011 study served as a launching pad for the work of a growing group of researchers worldwide who believe sunlight to be the key to keeping childrens’ eyes in working condition. According to Dr. Christopher Starr, an ophthalmologist from Cornell University’s school of medicine, exposing the eyes to sunlight may cause them to release dopamine, which serves as an inhibitor to eye elongation. Without a su cient amount of dopamine, the eyes continue to grow to a point where their lenses and retinas are no longer properly aligned, which results in nearsightedness. In extreme cases, the retina can be stretched to the point where it tears and detaches from its normal position, o en leading to permanent blindness. To counteract this, it is recommended that children get two hours of direct exposure to sunlight a day.

However, with summer now in full swing, that much exposure to the sun can also cause damage if you aren’t careful, as ultraviolet (UV) radiation is most intense during this season. While most people are aware of the harm that UV light can do to their skin, there are also many eye complications that can develop due to UV overexposure as well, such as cataracts or eye cancers. ese diseases o en appear later into one’s life, but spending too much time in the sun without being properly protected can drastically increase the risk of contracting them. To lower the chance of developing these eye issues, optometrists recommend wearing broad-brimmed hats and sunglasses with 100% UV protection. Avoiding the outdoors during midday to early a ernoon can also reduce your exposure to UV rays, as that’s when sunlight is normally the strongest.

As teenagers, our eyes are still growing. In fact, they’ll continue to do so until around 20-21 years of age, so even if you’ve already developed rather advanced nearsightness, it’s still a good idea to get an adequate amount of daily sunlight to prevent it from getting any worse, among the other bene ts of getting some occasional sunshine. Research into the relationship between the exact mechanism between sunlight and myopia is ongoing, but there is already a strong body of evidence supporting its bene ts to our eyes. So next time your parents nag you about getting o your screen, just take it outside where they can’t bother you about it anymore. It’s good for you, as long as you keep everything in moderation — both screentime and sunshine!

Photo: David Travis