Cosmetic contact lenses may add an extra bit of flair to a Halloween costume, but one Bronx doctor says they can be dangerous if misused or even applied at all.

"Every year, unfortunately we see an increase of patients who come in with minor scratches or severe scratches, infections," says Dr. Jimmy Lee, the director of cornea and refractive surgery at Montefiore Medical Center.

Cosmetic contacts must be prescribed by a health care professional who properly fits them, he says, as one size does not fit all.

"I would say there is no instance with costumes where you should be wearing colored or cosmetic contact lenses," Lee says.

The worst possible case, according to Lee, is a complete loss of vision if someone buys and wears the lenses without any consultation.

The Food and Drug Administration says anyone who plans on using colored contacts should see an eye doctor and receive a prescription. It urges people to avoid buying cosmetic lenses from street vendors, beauty stores, Halloween shops and online retailers.

Lee has stronger advice for anyone wishing to use decorative lenses: "Stay away from them."