JiMarti sunglasses start at $13. It's easy enough to pick up a pair of inexpensive sunglasses at a clothing store or mall kiosk -- or even a gas station convenience store. Good sunglasses, however, are more than mere fashion accessories. Doctors warn that the same ultraviolet rays that cause skin cancer can also seriously harm your eyes, so it's crucial to wear sunglasses with full UV protection. Features designed to eliminate glare or prevent lenses from cracking can also be found in sunglasses that don't cost much more than the average designer knockoff. Below are Cheapism's top picks for affordable sunglasses. JiMarti sunglasses (starting at $13) cater to outdoor enthusiasts with sleek wraparound styles and impress consumers posting reviews online with their overall quality and fit. Many models boast features such as mirrored lenses or scratch-resistant coating. All of them come with a 30-day money-back guarantee and lifetime breakage warranty. Sunbelt sunglasses (starting at $20) include models made specifically for children, as well as men and women. Reviewers deem the sunglasses both fashionable and comfortable, and they're backed by a limited lifetime warranty. Black Flys sunglasses (starting at $17) attract repeat buyers with their style, performance, and durability. According to online reviews, consumers find them effective at shielding their eyes from the sun and screening out glare. Nike sunglasses (starting at $30) can certainly get expensive, but even low-end models win favor for their sporty style and superior comfort. They come in various tints designed for different activities. Some have ventilated nosepieces to keep the lenses from fogging up. All the brands on this list make their sunglasses with polycarbonate lenses, which are lightweight and won't distort your vision. Perhaps most important, polycarbonate is far more impact-resistant than regular plastic, so you don't have to worry so much about the lenses getting crunched when you play a sport or bury your sunglasses at the bottom of a bag. Coupled with a warranty, this durable material can help keep you from constantly having to shell out for new shades. Read the label or product description closely. Experts recommend buying sunglasses that offer 100 percent UV protection, or close to it. You may also see lenses labeled as "UV400," which means the same thing (it protects against wavelengths up to 400 nanometers). If the level of UV protection is somewhat vague or you don't see any mention of UV protection at all, it's best to choose a different pair. Some models made by the above brands feature polarized lenses, which filter out glare from the sun on water or snow or wet roads. An anti-reflective coating on some JiMarti sunglasses serves a similar function. The brands listed above also make sunglasses with tinted lenses. The effect of each tint goes beyond aesthetics. For example, yellow increases contrast and makes everything look more vivid but doesn't render color accurately. Eye-care professionals often recommend a gray tint to reduce brightness without distorting colors. More from Cheapism: Cheap sunglasses Mosquito trap reviews Cheap computer cable recommendations Cheap backyard pools