Cosmetic contact lenses change the color of the eye's iris. They can be used solely for cosmetic reasons (to make brown eyes blue, for instance) or to correct vision issues as well. Companies have developed "cinematic," or "theatrical," lenses that are reflective, and change the shape of the pupil for use in Hollywood films.

Cinematic lenses are often used in movies and stage productions that call for a distinctive eye color or trait. In "The Chronicles of Riddick," Vin Diesel's character wears mirrored contact lenses.

Special effects contact lenses can be purchased widely on the Internet without a doctor's prescription. Mirrored lenses are also easily available, but many cannot adjust for vision correction: If a wearer's vision isn't naturally 20/20, a prescription usually can't be included in effects contact lenses.

Mirrored contact lenses should be handled with extreme care, and extra precautions should be taken not to damage or tear the lens. Otherwise, special effects contacts may be handled and cleaned in a similar manner to corrective lenses. Saline solution and contact cases should be kept clean and sterile.

A few measurements are required in order to adequately size and fit special effects contact lenses to a wearer's eyes. The eye's iris diameter size and pupil size (in millimeters), keratometry readings and iris color must be supplied. These measurements may be taken at any optometrist's office.

A number of online retailers carry the reflective lenses worn by Vin Diesel in "The Chronicles of Riddick." 9mm SFX specifically retails the exact style, touting its lenses as wearable for years (if properly cared for). Fashion-ContactLenses.com sells mirrored silver contact lenses.