Next time you go shopping for sunglasses, make sure that you are choosing the one you require most and one that is perfect for your kind of eyes. While it is true that sunglasses offers protection against the harmful rays of the sun, many of them found in the shops might not serve the right purpose.

Dr. Amir Khan, MD, and an ophthalmologist with Mayo Clinic, provides a better understanding of some of the key aspects that one might need to consider while purchasing sunglasses to help ensure good eye health.

In the latest issue of Mayo Clinic Women’s HealthSource, Dr. Khan reiterates that ultraviolet (UV) rays from the sun can harm the skin and the eyes with long-term exposure to UV rays increasing the risk of cataract. Cataract results in clouding of the lens and poor vision. UV rays are also linked with increased risk of macular degeneration -- a condition that leads to blindness.

Sunglasses are an easy and effective way to protect against UV rays. “It’s best to wear sunglasses any time you’re outside and need sun protection,” says Dr. Khan. However, you need to be sure that the sunglasses do protect to the desired levels. Here are five tips to ensure that you make the right choice while purchasing those shades:

1) Check the label: The labels placed on sunglasses usually provide with some information about their quality. See if it mentions the UV factor. Go for sunglasses that block both UVA and UVB, the two types of UV rays found in sunlight. The sunglasses should block 99 to 100 percent of these rays. It is best to avoid the ones which do not even boast of such a claim.

2) Glare reduction: Polarized lenses can cut the glare that reflects off shiny surfaces. Glare shielding glasses are always welcome. But reducing glare has nothing to do with UV protection. So, ensure that the pair of glasses offers UV protection in the first instance, along with glare prevention.

3) Lens color: Dark colored lenses are okay. Darkness, however, is not indicative of UV protection. In fact, the coating that blocks UV light is clear.

4) Good fit: Glasses that fit properly around your eyes will offer you the maximum protection as they can block the most UV radiation. Pick up shades that cover most of your eyes from the top as well as the sides.

5) Price: Remember the fact that higher price does not always indicate desired quality. Here the most important requirement is better UV protection. The high costs mentioned on the labels could be a fashion statement.