An hour a day

Near-sightedness, or myopia, is the most common refractive error of the eye, and it has become more prevalent in recent years.

In fact, a recent study by the National Eye Institute (NEI) shows the prevalence of myopia grew from 25 percent of the U.S. population (ages 12 to 54) in 1971-1972 to a whopping 41.6 percent in 1999-2004.

Though the exact cause for this increase in near-sightedness is unknown, many eye doctors feel it has something to do with eye fatigue from computer use and other extended near vision tasks, coupled with a genetic predisposition for myopia.

If you are nearsighted, you typically will have difficulty reading road signs and seeing distant objects clearly, but will be able to see well for close-up tasks such as reading and computer use.

Other signs and symptoms of myopia include squinting, eye strain and headaches. Feeling fatigued when driving or playing sports also can be a symptom of uncorrected near-sightedness.

Myopia occurs when the eyeball is too long, relative to the focusing power of the cornea and lens of the eye. This causes light rays to focus at a point in front of the retina, rather than directly on its surface.

Near-sightedness also can be caused by the cornea and/or lens being too curved for the length of the eyeball. In some cases, myopia is due to a combination of these factors.

Myopia typically begins in childhood and you may have a higher risk if your parents are nearsighted. In most cases, near-sightedness stabilizes in early adulthood but sometimes it continues to progress with age.

With more and more people getting nearsighted these days, there is a lot of interest in finding ways to control the progression of myopia in childhood.

In ground-breaking new research has confirmed the role of outdoor light in reducing short-sightedness in children.

Increasing exposure to outdoor light is the key to reducing the myopia epidemic in children, according to ground-breaking new research by Australian optometrists.

Optometrist and lead researcher on the project, Associate Professor Scott Read, who is the director of research at QUT’s School of Optometry and Vision Science, said that children need to spend more than an hour and preferably at least two hours a day outside to help prevent myopia from developing and progressing.

Speaking over the weekend at the Australian Vision Convention in Queensland, Assoc. Prof. Read explained it was not ‘near work’ on computer and other screens causing myopia, but a lack of adequate outdoor light.  While screens are contributing to children spending more time indoors than in previous years, the research shows they are not the direct cause of the increased incidence of myopia.

“Optometrists need to make their patients aware that less than 60 minutes’ exposure to light outdoors per day is a risk factor for myopia,” he said. “It looks like even for those with myopia already, increasing time outside is likely to reduce progression.”

President of Optometry Australia, Kate Gifford said “this new finding is of significant importance in our endeavour to mitigate the growing rate of myopia in children.”

In February, it was announced that half the world’s population will be short-sighted by 2050 with many at risk of blindness. The global study, published by the Brien Holden Vision Institute, forecasts that 10 per cent of the world’s population will be at risk of blindness by 2050 if steps aren’t taken to stop myopia turning into high myopia (requiring glasses with a prescription of minus 5 or stronger).

The QUT study measured children’s eye growth via study participants wearing wristwatch light sensors to record light exposure and physical activity for a fortnight during warmer then colder months to give an overall measurement of their typical light exposure.

“Children exposed to the least outdoor light had faster eye growth and hence faster myopia progression,” Professor Read said.

“The work of Scott Read and his colleagues is an exciting development and the onus is now on optometrists to help spread the message of the one-hour-a-day prescription of outdoor light,” Mrs Gifford said.

For more information on optometry services in Australia, including finding your local optometrist, visit www.optometrists.asn.au