Halloween costumes can be very elaborate, and for some, decorative contacts may seem like the perfect accessory to complete a look. What many people may not realize; however, is that contacts are medical devices regulated by the FDA and it is illegal to sell them in the United States without a prescription.

What exactly are decorative contacts? They range from color contacts—blue, green, purple, white, etc.—to contacts that give you the look of zombie or cat eyes.

It is safe to purchase them from your optometrist or ophthalmologist, as they can find the proper fit for your eye. You can also purchase these contacts online, provided that the site requires you enter your prescription.

According to the FDA, a poor fit can cause serious damage, including:

• Scratches on the cornea
• Corneal infection
• Conjunctivitis (pink eye)
• Decreased vision or blindness

Remember, decorative contacts should never be purchased without a prescription. As with regular contacts, proper care and hygiene is important when handling decorative contacts. If you develop signs of possible eye infection -- redness, eye pain that doesn't go away after a short time and a decrease in vision, see your doctor immediately.