The people trying to perfect a scary look this Halloween with cosmetic contact lenses purchased at party stores should think twice about doing so, say opticians who warn they can cause serious problems.

Registered optician Lorne Kashin says that contact lenses are medical devices, which he thinks people seem to forget at Halloween.

"Sticking a piece of plastic in your eye," which doesn’t fit, or which may be dirty, can cause a lot of complications, Kashin says.

“You could lose your sight very easily,” says Kashin.

Registered optician Lorne Kashin

Registered optician Lorne Kashin said that people seem to forget that contact lenses are medical devices. (CBC)

The U.S. Food and Drug Administration warns that any type of contact lenses can cause damage to your eyes if they aren’t used properly.

The FDA has also created a YouTube video to explain to the public the kinds of risks they need to consider when using decorative lenses.

Here in Canada, the federal government passed a bill last December to classify cosmetic contact lenses as medical devices. But until the regulation is in place, they can still be purchased at many stores.

Click on the video above to see a full report from the CBC's Natalie Kalata.