Sunglasses are marrying function with fashion. Accessories designer Kate Spade recently launched her own signature line, featuring (left to right) Bella, a tortoise-shell version of Pauline, Carine and a colored version of Pauline.

"Use the same rules that you use for a blouse and your makeup," she says.

She also suggests keeping the frame in line with your haircolor: tortoise-shell for dark brunettes and red for redheads.

Right now, rimless sunglasses are a popular trend, as are anything big, observes Norbeck.

"You can always buy the right trend for yourself."

"The design philosophy behind Mont Blanc's sunglasses is that they will last much longer than a season -- unlike some of today's disposable clothing -- so the eyewear evolves but never radically changes," explains Marion Davidson, senior vice president of marketing.

When you find a shape that fits your face, you generally stick with it and will look for only small variations when you buy a new pair, she says.

Mont Blanc's newest offerings are basic enough to almost be labeled unisex. There's the "Comete," a 1960s-inspired oval shape that was initially designed with women in mind; the "Eclipse," a less retro, more rectangular shape that also was designed for women; and the "Planete," men's wire-based glasses in a rectangular shape.