Is seeing life through rose-colored sunglasses right for you? It might be if you're a fan of early-morning bike rides or if you're a commuter at dusk.

Choosing new summer shades is more than an issue of flattering frames. There are decisions to be made about the lenses, too, and there will only be more in the future.

Things to think about: Are your sunglasses more for performance or fashion? (You don't necessarily need to choose.) Are you concerned about glare or definition? Do you want a curved lens that provides maximum coverage or a flatter one that allows more peripheral vision?

Will gray, green or rose be a better match for your lifestyle? Each is best suited to handle particular conditions and activities.

"Lenses can affect - and can enhance - performance. Sports performance is the biggest category for shopping by lens color and treatments, and most fashion lenses are still browns and grays," says Dr. Justin Bazan, a New York optometrist and medical adviser for The Vision Council, a trade group for the optical industry. "I can imagine it happening, though, that the tint options that have exploded in sports will soon come to fashion purchases."

Roberto Vedovotto, the CEO of Safilo Group, parent company to sunglass brands Carrera, Smith Optics and Polaroid and the licensing partner for designer labels Gucci, Dior and Marc Jacobs, agrees that it's on the cusp.

Customers, he says, are becoming more educated about ultraviolet light - largely because of great strides in sunscreen use, and they are aware that the technology exists to improve sunglass lenses. People are very aware overall about protecting themselves from the sun.

Polarization makes sense for many runners, beach-goers and drivers because it will reduce the glare of light coming from the water, road or sand, he explains. They're also good for fishermen who need to see beneath the surface.

A skier, however, who needs to see the shine and shadows of the snow and ice, might want a non- polarized lens.

Sammy Bryant, retail business developer for Adidas Eyewear, says golfers also steer away from polarization because peripheral vision is important on the greens, and a lens with that treatment will have a more noticeable difference between what you see through the glasses and the corner of your eye.

The curve of a lens is going to matter, too, Bryant says. It's measured on a scale of one to 10, he explains, common for reading glasses - which are pretty much straight from end to end - at a five and ski goggles at a nine. Higher numbers give better protection and cover a wider range of view, but curve can add some distortion.

Color is also a factor, according to Nick Gomez, senior product manager of Under Armour Performance Eyewear. While green lenses might be good for the ballfield - there's better balance of background and the target object - brown ones are good for hiking or mountain biking because they offer improved depth perception, he says.

"Personal preference is what's going to drive this. You have to try them on," Bazan says.