More sunlight exposure reduces risk of shortsightedness

August 12, 2014 by Rogini Moorthi, Science Network WA
Ongoing research aims to outline what the best amount of time is to spend outdoors for overall health. Credit: Ed Yourdon

The more time adolescents and young adults spend outdoors exposed to sunlight, the lower their risk of being shortsighted (myopic) is, eye experts have found.

Researchers used conjunctival ultraviolet autofluorescence (a measure of to the eye), to measure how much light gets onto the eye to investigate the association between myopia and outdoor activity.

The study comprising 1344 from WA's Raine Cohort Study used a new camera system developed by UNSW's Professor Minas Coroneo to take ultraviolet photographs of the participants' eyes.

These photographs were then used to assess the sun damage to the surface of the eye.

Lions Eye Institute Managing Director David Mackey says conjunctival ultraviolet autofluorescence (CUVAF) is a more objective and accurate method of measuring than questionnaires, which have been used in other studies.

"There might be bias in a research study if the participants played down the amount of time they spend outdoors," he says.

Professor Mackey says 20 per cent of the WA population is myopic, while over 90 per cent of the young adult populations in Asian countries, such as Singapore, are myopic.

"Having a large number of people who are shortsighted increases the risk of blindness from other diseases such as glaucoma, macular degeneration and retinal detachment," he says.

Prof Mackey says while it is not fully understood how outdoor activity prevents myopia, there are various theories to explain the association.

"One theory is that the direct effect of the UV light on the front of the eye changes the structure of the wall of the eye."

"Another theory is that exposure to sunlight results in the retina releasing the chemical dopamine, which stops the eyeball from growing excessively and blocking the focus of light entering the eye," he says.

While the CUVAF photographs showed evidence of sun damage in the eyes of those participants who had higher exposure to sunlight, it also found that more exposure to sunlight decreased the odds of myopia.

However, Prof Mackey says encouraging people to spend a lot more time outdoors could also increase the risk of skin cancer and can lead to eye diseases such as pterygium—a growth in the conjunctiva of the .

"Thus, part of the aim of our ongoing research is to come up with a balance and work out what is the right amount of outdoor activity people can have," he says.

Explore further: Eyes on the sun: Child sunshine exposure and eye development

Related Stories

Eyes on the sun: Child sunshine exposure and eye development

May 21, 2013
(Medical Xpress)—Exposure to sunshine as a small child is crucial to the development of a healthy eye according to results of long-term myopia study conducted by University of Sydney researchers.

Bounty mutiny descendants have low rates of myopia: study

July 20, 2012
Descendants of a British mutiny who have lived for generations in the Pacific have among the lowest rates of myopia in the world, according to an Australian study.

Outdoor activities, day length tied to myopia onset, progress

June 27, 2013
(HealthDay)—Exposure to outdoor activities correlates with less new onset of myopia and myopic shift, and the number of hours of daylight is associated with eye elongation, myopia progression, and corneal power change, ...

Increased nearsightedness linked to higher education levels and more years spent in school

June 26, 2014
German researchers have found strong evidence that attaining a higher level of education and spending more years in school are two factors associated with a greater prevalence and severity of nearsightedness, or myopia. Published ...

Don't skimp on shades this summer

July 18, 2014
Sunscreen and sunglasses top the list of summertime must-haves for most people. But just as skin can burn on an overcast or chilly day, eyes can sustain damage anytime you're outdoors without sunglasses.

Outdoor recess time can reduce the risk of nearsightedness in children

May 1, 2013
Two new studies add to the growing evidence that spending time outdoors may help prevent or minimize nearsightedness in children. A study conducted in Taiwan, which is the first to use an educational policy as a public vision ...

Recommended for you

Researchers are one step closer to developing eye drops to treat age-related macular degeneration

July 19, 2018
Scientists at the University of Birmingham are one step closer to developing an eye drop that could revolutionise treatment for age-related macular degeneration (AMD).

An orange a day keeps macular degeneration away: 15-year study

July 12, 2018
A new study has shown that people who regularly eat oranges are less likely to develop macular degeneration than people who do not eat oranges.

Injectable electronics offer powerful new tool in understanding how retinal cells work

June 28, 2018
Charles Lieber and his group are rewriting the rules of how scientists study retinal cells, and they're doing it with a single injection.

Why the eye could be the window to brain degeneration such as Alzheimer's disease

June 26, 2018
Researchers from Queen's University Belfast have shown for the first time that the eye could be a surrogate for brain degeneration like Alzheimer's disease (AD).

Microglia protect sensory cells needed for vision after retinal detachment

June 18, 2018
A research team at Massachusetts Eye and Ear has shown that microglia, the primary immune cells of the brain and retina, play a protective role in response to retinal detachment. Retinal detachment and subsequent degeneration ...

161 genetic factors for myopia identified

June 15, 2018
The international Consortium for Refractive Error and Myopia (CREAM) recently published the largest-ever genetic study of myopia in Nature Genetics. Researchers from the Gutenberg Health Study at the Medical Center of Johannes ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.