Prevention of Myopia Progression
by Ren Chats
Myopia: Image is Focused In-front of Retina
Could progression of myopia, the nearsightedness, be prevented?
Beneficial effect of sunlight on children's eye health has been documented by recent study conducted in Denmark.
Denmark is located far north on the globe, where short hours of sunlight during major part of the year was clinically noted to cause worsening of nearsightedness among tween and teens of the country. Experimental results also supported this clinical observation.
Yet another study was conducted in Taiwan, where daylight is not a geographical issue, which proclaimed positive influence of outdoor activities on visual acuity of myopic children.
What has caused the confusion?
Benefits of sunlight, rather than sport per se, on visual acuity during childhood development has been an accepted fact over centuries. However, how exactly this positive effect is brought about has been a topic of research for decades.
Confusion set in when several reports emerged about ill effects of UV rays from the sun. Consequently outdoor activities were widely restricted for fear of chronic eye diseases and skin cancer.
Instead of outdoor games children are being increasingly exposed to electronic toys, television programs, video games et cetera, which is commonly noted as screen addiction even among preschool kids.
The study from Denmark brings forth direct correlation between duration of daylight exposure, eye growth and the rate of myopia progression.
Eyeball growth is constant throughout childhood development, but is remarkably slow and minute; 7.62 mm with 17.78 mm at birth to the adult size of 25.4. Even small errors in eye growth disturb its proportions and lead to refractive errors in children:
• Distorted or blurred vision, astigmatism
• Farsightedness known as hyperopia, where eye length is shorter than normal.
• Nearsightedness, myopia occurs when eye length is longer than normal.
Inadequate exposure to daylight promotes axial growth of eye balls, and thereby enhances myopia progression.
Myopia is the most common cause of visual impairment in children between 5 and 15 years of age, and it increases the risk of eye diseases as the age advances.
Results of the study indicate that longer period of activities for children out in the open daylight not only delays myopia progression, but also postpones its onset in children genetically predisposed to this visual acuity disorder.
Another interesting study has been conducted on school children in Taiwan. This is a prospective interventional study, where the intervention was that children spend recesses outside the classroom. One school participated in the intervention and the other school formed the control group. Control group was not required to follow any special program
Eyes examination at the beginning and end of the year showed that significantly fewer children developed myopia in children who spent their recesses outside the classroom as compared to the control group.
Both these studies indicate the importance of daytime outdoor activities in prevention of myopia progression. Remarkably a simple solution to a distressing visual impairment during childhood. Therefore, children should not only be watched for vision defects, but also encouraged to spend more time outside in natural daylight.
1. Effect of Day Length on Eye Growth, Myopia Progression, and Change of Corneal Power in Myopic Children: Dongmei Cui, Klaus Trier, Søren Munk Ribel-Madsen. Ophthalmology, 2013; 120 (5): 1074 DOI: 10.1016/j.ophtha.2012.10.022
2. Outdoor recess time can reduce the risk of nearsightedness in children: Pie Chang Wu et al American Ophthalmology, 2013, doi.org/10.1016/j.ophtha.2012.11.009