With Every Hour Of Screen Time, The Odds Of Myopia Increases By 21%

A new study published in Jama Network Open suggests that spending more time staring at screen whether on smartphones, tablets or computers raises the risk of developing nearsightedness or myopia. Researchers found that for every additional hour of daily screen time, the odds of myopia increases by 21%. These findings also highlighted the growing concerns over digital screen use and its impact on eye health.

What Is Nearsightedness?

Myopia or nearsightedness is a common vision condition where close-up objects appear clear, but distant objects look blurry. As per a study published in the American Academy of Ophthalmology, as of 2022, 2.6 billion people worldwide have myopia. This is projected to increase to 4.758 billion by 2050, which is half of the world's population. People with myopia can read a book or map easily but struggle to see road signs or drive safely without corrective lenses.

The prevalence of myopia has been rising globally. Some believe that the COVID-19 pandemic is to be blamed as it allowed the shift towards a more virtual world, leading to an increase in screen time. Other than this, environmental factors, especially for those living in urban spheres play a major role. As urban lifestyle reduces time spent outdoors and increases in near-vision activities, such as screen use.

How Was The Study Conducted And What Did It Find?

To better understand the link between screen time and myopia, researchers conducted a comprehensive review of 45 studies involving over 335,000 people. The study found a clear dose-response relationship, meaning the more time spent on screens, the higher the risk of nearsightedness.

Key findings include:

• The risk of myopia increases significantly between 1 to 4 hours of daily screen time.
• After 4 hours, the risk continues to rise but at a slower rate.
• People who use screens for 4 or more hours a day have double the risk of developing myopia.
• The study also suggests a potential “safety threshold” of less than 1 hour of daily screen exposure, beyond which the risk starts to climb sharply.

Screen Time And Eyes

Screens have introduced almost everyone of us to new forms of near-work activity that differ from traditional task of reading and writing. Now, you can achieve that too on your screens. While it can be handy, not carrying a book, a pen or paper, and having everything at once on your device, it can do more harm to our eyes than we know.

This is also because digital screens emit blue light, cause glare and often require prolonged focus, all of which may strain the eyes. Researchers have also emphasized that screen time alone, however, is not the only factor. There are other near-vision activities like studying or drawing that too can contribute to myopia. This suggests that simply by replacing screens with other close-up task is not enough to prevent this condition.

However, screen time does more harm because of the blue light emission. As children are increasingly exposed to digital devices now, at a very younger age, it can impact their vision health. Researchers thus are stressing to reduce the overall near-work-activities and increase outdoor time as much as it could, as an effective strategy to curd myopia stress.