Sunglasses are important year round, but especially so during summer months when we tend to spend more time outdoors. When you shop for sunglasses, one of the things that makes a big difference in price is whether or not the lens is polarized, which might lead you to believe that polarized is better for your eyes. That's not entirely true.

You need to make sure that any sunglasses you purchase block UVA and UVB rays. Polarization has nothing to do with UV -- it simply prevents glare. And, while glare can cause you to squint (which can lead to eye strain and wrinkles), the glare itself isn't doing damage to your eyes.

Surfaces that tend to cause glare are pavement and water, so polarized is often preferred for driving and boating. Personally, I like polarized lenses for running outdoors, but I know other people who are bothered by the polarization, so if you're spending big bucks on glasses for running outdoors, make sure you're familiar with the return/exchange policy.
Your best bet is to find a pair that offers plenty of coverage -- wraparound styles will block the most light -- and with a lens dark enough to make it hard to see your eyes through the lens. If you want polarized lenses, don't be concerned that you'll only be able to find sporty styles. Polarized lenses come in all shapes and styles. Check out the gallery for examples!