(MONEY Magazine) – Take a walk down any sunny city street these days, or a ride on your local bike path, and you'll likely see more varieties of sunglasses than there are of Beanie Babies. What's up with that? "Sunglasses have become much more activity-specific," explains Richard Morgenthal, president of Morgenthal-Frederics Eyewear in New York City. That means now, more than ever, you need to buy shades with an eye toward your passion--be it serious competition or equally serious style. What's hot: futuristic sport-specific models, as well as sleek retro styles suitable for pounding city pavements. Typical price: $75 to $300.

For cycling, jogging and other sweaty sports, check out the new antifog wraparounds from such makers of sports glasses as Briko, Nike and Oakley. One of the best such models is Nike's new V12 ($145; pictured below). Its impact-resistant polycarbonate lenses are riveted to the frames only near the nosebridge. Because most of the lens is actually suspended in front of the frames, the design reduces fogging by increasing airflow between your face and the lens. The 1.15-ounce plastic frames, attached to thin stainless-steel temples with self-locking hinges, stay snug on your face even when you're working hard.

Because they're virtually unbreakable, polycarbonate lenses are ideal for sports in which glasses sometimes make unplanned connections with errant balls or elbows. Polarized lenses like those on Maui Jim's Sundance specs ($219), which eliminate reflective glare, are best for water sports like sailing, fishing and water-skiing.

Of course, sometimes you just want to look good while profiling around town. And this summer, that means looking like you stepped out of the '60s. Ray-Ban's Predator 2 ($99; pictured center), the newest offering from the venerable manufacturer of the once ubiquitous Wayfarer, supplies the proper dash. These classic black nylon-framed glasses with impact-resistant tempered-glass lenses are sported by Tommy Lee Jones and Will Smith in the new action movie Men in Black.

The must-have for stylish women is Gucci's Jackie O-inspired pair (model 2410, $130, pictured above). They're a bit smaller than Jackie's famous black shades, and the hand-finished plastic frames come in this season's best colors, including green, pearl pink and (our favorite) light blue. Both Goldie Hawn and Gwyneth Paltrow have been spotted wearing them.

Whichever pair--or pairs--you buy, remember that the most important feature of sunglasses is protection from the sun's damaging ultraviolet rays. "Buy only sunglasses that protect you from 99% of UVA and 100% of UVB radiation," advises Donald Pitts, an Oklahoma optometrist and leader in ultraviolet ray research.

--James E. Reynolds