Research is pointing toward a link between myopia and the brain chemical dopamine. All-natural sunlight may be the antidote.
Myopia is called “near sightedness” because the eyeball is too long. The image from the lens falls short of the retina, causing blurring of distance vision. The condition is corrected using glasses or contact lenses. It is on the rise all over the world. In the United States, incidence has risen from 25% to 50% of young adults in 50 years.1
It is a common belief that myopia can be caused by too much close-up work, such as reading. However, the link might actually be low dopamine. And it’s known that lack of sunlight reduces dopamine levels. So kids reading and studying indoors too much might be the culprit.
Research has looked into the direct effects of dopamine on eyeball development. A survey of the research found specific low dopamine was associated with elongated eyeballs in animal studies; and adequate dopamine associated with the correct length of the eye.2
Asia has an epidemic of myopia, with up to 90% of young adults having it. South Korea, for example, had an 18% rate among 20-year-olds in 1955; now it is 96%. Students have been spending more time studying indoors during this time period.
Elementary school students in Singapore spend only half an hour a day outdoors. Myopia rates are 90% of young adults. In Australia, outdoor time is three hours a day, and the rate of this eye condition among children of European origin is about 10%. Africa’s rate is close to 1%.[ Myopia (series), The Lancet. Volume 379, No. 9827, p1739–1748, 5 May 2012. Ian G Morgan et. al. DOI: http://dx.doi.org/10.1016/S0140-6736(12)60272-4]
In addition to adding more outdoor activities, a school in Guangdong province in China is experimenting with glassed-in classrooms. Making the rooftop transparent allows plenty of sunlight into the classroom. A school in Taiwan locked students out of the classroom at lunchtime, receiving a total of 80 minutes of outdoor play during each school day. Fewer students developed myopia compared to a control school.3
- The Myopia Boom, Nature, Vol 519, Issue 7543, Elie Dolgin. Padmaja Sankaridurg, head of the myopia program, Brien Holden Vision Institute, Sydney, Australia. ↩
- Exp Eye Res. 2013 Sep;114:106-19. doi: 10.1016/j.exer.2013.02.007. Epub 2013 Feb 19. An updated view on the role of dopamine in myopia. Feldkaemper M, Schaeffel F. ↩
- The simple, free solution to Asia’s myopia epidemic by Madison Park, CNN April 6, 2015 http://www.cnn.com/2015/04/05/asia/myopia-east-asia/ ↩