Women's glasses have evolved tremendously even in the last 15 years. Almost every major fashion designer offers a collection of women's glasses and women's sunglasses. Eyewear styles vary, but there are many traits that are common to all womens eyewear. For example, the contour lines of glasses frames tend to be softer, rounder, without sharp corners. Colors exist in a wide variety, from a sober palette of black, grey, brown and silver, to some wild combinations with all the colors in the rainbow. Colors are best shown on plastic glasses frames, and the trend in recent frames has been away from metals and toward the plastics, due to their softness and their much greater ability to bring a fresh color accessory to the face. Womens sunglasses have also developed tremendously, especially with the introduction and incredible popularity of womens designer sunglasses in the past 20 years.