Circle lenses are all the rage, but is the look worth the risk?

Lady Gaga is known for setting trends with her unconventional and often wild style. But the latest Gaga-inspired look—larger-than-life eyes like those seen in her "Bad Romance" video—has sparked a risky trend: the use of illegal contact lenses.

To achieve a doe-eyed gaze, thousands of young women and teens are rushing online to buy what are known as circle lenses. These special contacts, imported from Asia, make your eyes appear larger by covering not just the iris, but also part of the white area of the eye.

While the product may seem harmless—hundreds of users sing their praises online and share where to purchase the lenses for a mere $20 or $30 a pair—optometrists warn of harmful adverse effects.

"It's illegal to sell any contacts in the U.S. without a prescription, whether they're corrective or cosmetic," explained Dr. Michelle Calder-Cardwell of Urban Optiques in Northville, MI. The reason why? Without a proper fitting from an eye doctor, contact users risk eye infection, scratched corneas, and even permanent vision loss due to lack of oxygen from improper fit.

Because circle lenses are purchased online, the source and safety of the product is also questionable. "These lenses are not FDA-approved so there's no safety or sanitation guarantees," explained Dr. Calder-Cardwell. Until circle lenses are available in the U.S. and you have an authorized prescription, "the look simply isn't worth the risk."

Know a trend-lover who's still after the big, bright-eyed look? Try a few of these makeup tricks to make your peepers pop the safe and easy way:

• Line your lower lids just below your eyelashes to make the whites of your eyes appear larger.
• Brush your eyebrows up and slightly out to frame and wake up your eyes.
• Dot the inner corners of your eyes with a light shadow to conceal dark circles and make your eyes look bright and open.

Want more ways to dress up your eyes? Search for video tutorials online, like this one from Lancome's video blogger Michelle Phan, to find more fun looks and step-by-step instructions. But remember—leave those unsafe lenses alone!