Myopia, or nearsightedness, is a common eye disorder globally By 2050, half of the global population may be affected. Genetics, environmental factors, and modern lifestyle change play significant roles in its development.
Myopia, also known as nearsightedness, is one of the most common eye disorders globally. In myopic people, the image of distant objects falls closer to the retina, either as the eye is too long (axial myopia), the cornea is too convex or the index of refraction of the lens is too high (refractive myopia). In this the light entering the eye is not focused correctly and the distant objects look blurred.
The World Health Organisation (WHO) has predicted that by 2050, half of the population globally will be affected by Myopia or nearsightedness. The forecast has helped raise questions about the underlying causes and what are the things that can be done to mitigate this health crisis. The role played by genetics, environmental factors , and the modern lifestyle change are the main causes behind this issue.
The Role of Genetics
Genetics play quite a significant role in the development of myopia. It has been observed that children of myopic parents tend to have longer eyes and are more likely to develop myopia during their childhood or adolescence. The strong familial effects for refraction phenotypes are present across different populations with varying underlying distributions of refractive error. If neither parent wears glasses, the probability of their children developing a Myopia refractive error is about 7%. However, if both parents have myopia then the risk of their children reaches to about 70%. This stark contrast shows the influence of hereditary factors on one’s eye health
Environmental Factors
While genetics plays the role of setting the stage, environmental factors seem to have a profound impact on the development and progression of myopia. The rise of indoor lifestyles, increased screen time, and a higher focus on academic pursuits over outdoor activities have greatly contributed to the growing prevalence of myopia. TV screens, phones, and laptops emit light that combined with close-up focus and reduced natural light exposure affect eye growth detrimentally. Studies on the effect of reading on the rate of progression of myopia have shown conflicting results. One of the studies showed that school children, near work were not associated with worsening myopia while some myopic children who spent more time reading had faster rates of myopic progression. Therefore, the relationship between reading, near work and myopia is complex and poorly understood. Studies have shown that spending more time indoors is a key contributor to the rise in short sightedness. This indoor centric lifestyle limits the exposure to sunlight which is quite essential for healthy eye development. Natural light exposure triggers the release of Dopamine which is a hormone that regulates eye growth.
The Importance of Natural Light
Exposure to sunlight not only releases dopamine but also encourages focus on distant objects which helps in relaxing the eye muscles and reduces myopia progression. Spending time outdoors provides two important benefits like increased natural light exposure and the opportunity to engage in activities that require looking at far distances which supports normal eye development.
Controlling the Myopia Epidemic
While genetic predisposition cannot be changed, environmental factors are modifiable. Evidence suggests that spending at least two hours outdoors can greatly reduce the risk of myopia progression. In response to these findings- Taiwan launched the Tian Tian 120 program in 2010 which mandated 120 minutes of outdoor activity daily in schools. This helped in successfully reversing the prevalence of myopia in the country. So implementing similar programs and shifting the focus from purely academic achievements to a more balanced approach can include physical activities and reduced screen time.
Therefore, the anticipated increase in myopia cases by 2050 can be due to both genetic and environmental factors. Modern lifestyle changes, particularly the rise in screen time and reduced outdoor activities has led to an increase in this health crisis. However, by understanding and modifying environmental influences, particularly through increased exposure to natural light and outdoor activities, we can control and even reverse this trend. Continued research and innovative treatments offer hope in addressing this growing public health concern.
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