Sunglasses really aren't an optional summertime accessory, they're an essential prescription for eye health. Long-term exposure to the sun without proper protection can increase the risk of eye disease, including cataract, growths on the eye, and eye cancer. As summer gets underway, the California Academy of Eye Physicians and Surgeons (CAEPS) and the American Academy of Ophthalmology (AAO) share seven essential tips for buying the best sunglasses to protect your eyes.

• Choose sunglasses that block 99 to 100 percent of both UVA and UVB radiation. Labels can sometimes be confusing. Some indicate sunglasses offer "100 percent protection from UVA/UVB radiation", others offer "100 percent UV 400 protection." Rest assured, both will block 100 percent of the sun's harmful radiation.

• Doubt the UV protection label? Take your sunglasses to an optical shop. Most have a UV light meter that can test the UV-blocking ability of sunglasses.

• Buy oversized. The more coverage (in area) from sunglasses, the less sun damage inflicted on the eyes. Consider buying oversized glasses or wraparound-style glasses, which help cut down on UV entering the eye from the side.

• Don't be fooled by color. While dark lenses may look cool, they do not necessarily block more UV rays.

• You don't need to pass on cheap sunglasses. Sunglasses don't have to cost a lot of money to provide adequate eye protection. Less expensive pairs marked as 100 percent UV-blocking can be just as effective as pricier options.

• Don't forget the kids. Children are just as susceptible to the sun's harmful rays as adults. Start them on healthy habits early.

• Consider polarized lenses. Polarization reduces glare coming off reflective surfaces like water or pavement. This does not offer more protection from the sun but can make activities like driving or being on the water safer or more enjoyable.

Even short-term exposure can damage the eyes. Sun reflecting off water (like from the surface of a pool or lake) can cause a painful sunburn called photokeratitis on the front part of the eye. It causes redness, blurry vision, sensitivity to bright light, and, in rare cases, even temporary vision loss.

"Think of sunglasses as sunscreen for your eyes," said Dianna Seldomridge, MD, clinical spokesperson for the American Academy of Ophthalmology. "Your eyes need protection from the sun's damaging ultraviolet rays just like your skin. Make sure your eyes are protected year-round. Harmful UV rays are present even on cloudy days."

"Protecting yourself from potential eye damage is as easy as donning a cool pair of shades, said Amin Afshrafzadeh, MD, CAEPS President and a Cornea and External Disease specialist practicing in Modesto. "You shouldn't ignore this simple way to limit your risk for eye damage."