Tuesday, November 10, 2009

Take Your Eyes Outside

Since I am nearsighted myself, I was intrigued by a recent article in New Scientist that looked at the causes of myopia (nearsightedness). Myopia rates have skyrocketed around the world, explained author Nora Schultz in "Generation specs: Stopping the short-sight epidemic," affecting 80% of the population in some Asian countries and 30% to 50% of the population in Western countries.

Researchers once thought that reading and other "near work" might cause myopia, but they have been unable to prove this definitively. Schultz writes that they have found that myopia is less common in children who spend more time outdoors, though.

Why is this? It doesn't seem to matter whether or not the children are getting any exercise outdoors, she explains. Instead, researchers believe that exposure to bright natural light might slow eyeball growth, preventing a child's eyes from growing into a shape that can cause myopia.

Focusing on far-away objects outdoors also might help prevent eye problems. Children who live in urban areas have fewer opportunities to look out over long distances than those who live in the country. This might contribute to high rates of myopia in urban areas.

So there is it, yet another argument to get outside and play in nature: it's good exercise for your eyes. A recent family trip we took to Marin County's Point Bonita Lighthouse was certainly a good example. To get there, we had to hike down a long trail that dropped off to crashing surf far, far below. We stopped at the edge of the trail a few times to peer down at the tiny fishing boats making their way toward the Golden Gate Bridge. The trail ended at a long, dark tunnel blasted into the cliffside.

We came out of the tunnel, squinting at the light, into a small gathering area with a group of other people. From there it was a short trip over a weather-beaten footbridge that the park rangers warned could only hold two people at a time, below which the surf crashed and spit into the rocks. I held my daughter's hand and walked carefully across (trying not to think about how much or how little money the National Park Serivce spends on repairs and maintenance each year), only looking forward at the cottage-sized lighthouse glued to a hunk of rock ahead of me because I really didn't want to look down.

Sure, there was a lot of bright natural light, and plenty of long scenic views from the lighthouse. But with the heights, the damp tunnel, the waves clawing at the cliff, and the rusty footbridge, I don't think I'll be back. I think our next trip will be to a nice peaceful meadow - inland.

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