Reduce Risk of Nearsightedness

Here's one good reason to turn off the Wii or Game Boy: Eye experts increasingly believe that
time spent outdoors could reduce the likelihood that children will develop myopia, or
nearsightedness, a condition in which distance vision is blurred.

"Your mother was doing the right thing when she said, 'Go outside and play,' " says Earl Smith,
dean of the College of Optometry at the University of Houston.

Myopia is on the rise around the world. A recent study found that in Americans ages 12 to 54,
the prevalence of myopia increased 66% between 1970 and 2000. Asia has also experienced a
sharp jump in nearsightedness in urban areas. "Nearsightedness is showing up at younger ages
and at higher progression rates," says Thomas Aller, an optometrist based in San Bruno.
Though myopia has a strong genetic component, genes alone cannot explain these increases.
"It's not all your family history, it's not all your outside time, it's not all your near work," says
Susan Vitale, a research epidemiologist at the National Eye Institute of the National Institutes
of Health. "All those things work together in a complicated way that we don't really understand
yet."

"Near work" activities, such as reading and computer use, have long been considered the most
likely culprits. But recent studies indicate that the amount of time children spend outdoors
could play an important role as well. One recent example: A 2008 study in the journal
Ophthalmology found that 12-year-olds who spent more than 2.8 hours outside per day on
average were less likely to have myopia than those who spent less time outside, regardless of
the amount of time they spent doing near work.

One possibility is that the eyes need exposure to a certain amount of light intensity; another is
that spending time outside exposes the eyes to objects that are consistently focused in the
distance.

Optometrists and researchers are developing a new arsenal of treatments that they hope will
slow myopia's progression. These include specialized eyeglasses and contact lenses, new types
of bifocals, specialized eye drops and contact lenses to be worn at night to reshape the cornea.
But even with these promising technologies, there is no way yet to prevent nearsightedness or
any drug to reverse it. Ultimately, scientists hope that through better understanding of the
interplay of genetics, environmental factors and eye function, the effects of nearsightedness on
lifelong vision can be reduced.

Source: Los Angeles Times February 13, 2011
By Amanda Leigh Mascarelli, Special to the Los Angeles Times