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.

Things to think about: Are your sunglasses more for performance or fashion? 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 it be gray, green or rose? Each is best suited to particular activities.

"Lenses can affect — and can enhance — performance," says Dr. Justin Bazan, a New York optometrist and medical adviser for The Vision Council, a trade group.

That means knowing when polarized lenses, which act as blinders to horizontal rays, make sense and when they might not.

Enthusiasts of water sports, including surfing and sailing, are Hobie Polarized’s most discerning shoppers. They want anti-reflective lens coatings, another coating to shed water and the evenness — almost flatness — of polarization, says Dustin Mora, senior product line manager.

Polarization makes sense for many runners, beachgoers and drivers because it reduces 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.

Sammy Bryant, retail business developer for Adidas Eyewear, says the curve of a lens is going to matter, too. It’s measured on a scale of one to 10, he explains. Reading glasses — which are pretty much straight from end to end — are commonly 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 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 ball field — better balance of background and target object — brown is good for hiking or mountain biking, offering improved depth perception, he says.

Generally, gray lenses, maybe with a hint of green, block the brightest rays, and brown are almost as effective but have a slightly warmer effect. Gomez says brown might be the most versatile.

Rose helps brighten overcast days and can be particularly helpful in the early morning or near sundown. Yellow has a similar effect. Blue and green provide a view that is truer to natural color, but might not curb bright light as well as gray.