Sunglasses offering full UV protection can range from a couple of dollars to hundreds of dollars. Do the more expensive models give you more protection?

Inexpensive sunglasses may not set the fashion world on fire, but they do serve a real purpose.

If you lose them at the beach, accidentally sit on them or drop them, and you're only out a few dollars. Also, most cheap sunglasses have tags claiming to give you protection from the sun's ultraviolet rays.

Most even claim to offer the same amount of protection you'd get from sunglasses costing as much as 10-times more.

That protection is important, because UV radiation emitted by the sun can be harmful to both the front and back of the eye. Exposure to UV radiation can cause photokeratitis, which is like a sunburn on the front of the eyes. Also, UV radiation can cause cataracts and retina damage.

So NBC reporter Liz Crenshaw decided to do a little comparison test, to find out if cheap sunglasses really protect your eyes from dangerous UV rays. Apex Optical.

Apex Optical's owner, Mike Pelivanis is an optician with more than 40 years of experience. He put the inexpensive sunglasses under his machinery to find out if they really gave the UV protection they claimed.

The first pair, a brand called Panama Jack Ultraflex, cost $16. The label claimed the glasses provide 100 percent UV protection.

The process to check sunglasses for UV protection took about two minutes per pair. When the checking was done, it turned out the $16 sunglasses blocked UV rays with the best of them.

The next pair tested cost $11-dollars. After a few moments of checking, they turned in a protection rate of 99 percent.

The following tests showed the same results. Even the $2 pairs delivered 99 percent protection.

Eye doctors said the test results didn't surprise them. The amount that sunglasses cost doesn't necessarily correlate with the amount of protection, nor does the darkness of the sunglasses. So a cheaper pair of sunglasses can have 99 percent to 100 percent UV protection and that's perfect

Experts also recommend buying sunglasses with labels saying they block both UV-A and UV-B rays. They warn that polarized lenses prevent glare but not necessarily UV penetration, and tinted lenses might not block UV rays either.

If you're questioning the amount of UV protection, Creshaw says you can take sunglasses to a qualified optician and a lot of times they'll be able to check them for you, to make sure the labeling is correct.