(Washington, DC) -- The FDA is urging people to be careful when buying decorative contact lenses. The agency is out with a list of dos and don'ts just in time for Halloween. The agency is reminding anyone going for the Twilight Vampire look or just changing eye color that the lenses are medical devices and they can only be sold with a prescription. The FDA says never buy fashion contact lenses that are illegally being sold by beauty salons, street vendors or over the Internet. The complete list of tips is available online at www.fda.gov/ForConsumers.