Screens have become an integral part of our everyday lives, and recent research highlights their potential impact on eye health. A study published in JAMA Network Open has identified a connection between prolonged screen exposure and an increased risk of myopia, commonly known as nearsightedness. This condition is characterized by clear vision of nearby objects, while distant objects appear blurry.
Study Overview and Key Findings
The study involved a meta-analysis of 45 studies, encompassing over 335,000 participants with an average age of 9. The findings indicate that just an additional hour of daily screen time can elevate the risk of developing myopia by 21%. The risk escalates significantly with one to four hours of screen use per day, and continues to rise, albeit more gradually, with over four hours of daily screen exposure.
A survey of 1,000 individuals revealed that Americans spend more than five hours daily on their phones, underscoring the prevalence of screen use in modern life.
Impact of Screen Time on Eye Health
Experts have long warned about the detrimental effects of excessive screen use on eye health. Digital eye strain, often resulting from smartphone use, can lead to symptoms such as dry eyes, itching, and blurred vision. The study authors suggest that linking screen time to myopia risk could offer valuable insights for future research and inform public health strategies. This is particularly crucial as projections estimate that half of the global population will be myopic by 2050.
Laura Ann Goldberg, OD, an assistant professor of ophthalmology at Johns Hopkins Medicine, emphasized the importance of this information for eye care providers. It enables them to educate patients and guardians about the increased risk of myopia associated with each additional hour of screen time, providing scientifically backed guidelines for managing children’s screen exposure.
Understanding the Screen-Myopia Connection
Victoria Tseng, MD, PhD, from the UCLA Stein Eye Institute, noted that while the correlation between screen time and nearsightedness is well-documented, the underlying mechanism remains unclear. Further research is needed to fully understand this relationship.
One hypothesis suggests that screens contribute to myopia because they are typically positioned close to the eyes. Studies have shown that activities involving “near work,” such as reading or watching TV, are linked to myopia, especially in children. During the pandemic, children engaged in online schoolwork experienced more significant myopia progression compared to those who did not.
Tseng explained that issues with “accommodation,” or the eye’s adjustment to focus on close objects, might play a role. An imbalance in the demand and response for accommodation, known as accommodative lag, could stimulate eye growth, leading to increased myopia.
Additional Factors Influencing Myopia
Goldberg highlighted that the type of screen is less significant than the viewing distance. Children often hold devices closer to their faces than physical books, exacerbating the issue of near work. Moreover, artificial light from screens can disrupt sleep quality, affecting melatonin levels and circadian rhythms, both of which are thought to influence myopia progression.
While smartphones and tablets are frequently discussed, they are not the sole contributors to myopia. Tseng pointed out that previous studies have suggested that computer and television use may pose a greater risk for myopia development than smartphone use.
Consequences and Recommendations
Nearsightedness can be corrected with contact lenses or glasses, but it can also lead to other eye health issues. Tseng warned that myopia increases the risk of retinal tears and detachments, glaucoma, and strabismus, which is the misalignment of eye muscles.
Prolonged screen use can also cause glare sensitivity, eye discomfort, headaches, and fatigue. There is a strong association between digital screen use and dry eye disease, as extended screen time reduces blinking, leading to faster evaporative loss.
To mitigate the risk of myopia, limiting screen time is advisable. The study suggests that spending less than one hour a day on screens could serve as a safety threshold for reducing nearsightedness risk. This aligns with existing recommendations for children’s screen time, as the American Academy of Child and Adolescent Psychiatry advises caution.
Practical Tips for Reducing Eye Strain
For adults, especially those whose work involves extensive screen use, reducing screen time can be challenging. However, adopting certain habits can alleviate eye strain. Tseng recommends blinking frequently, using moisturizing eye drops, and following the 20-20-20 rule: every 20 minutes, look at an object 20 feet away for 20 seconds.
By understanding the impact of screen time on eye health and implementing these strategies, individuals can better protect their vision in an increasingly digital world.
🔗 **Fuente:** https://www.health.com/screen-time-higher-risk-of-nearsightedness-myopia-11691977
