Contact lenses are delicately crafted, very thin optical discs generally smaller than a dime, worn directly on the eye. They are comfortably held in place by a natural layer of tears present between the contact lens and the cornea.

Contacts eliminate the barriers encountered with eyeglasses that interfere with the line of sight above, below and to the sides of the eye. Contacts restore peripheral vision and can reduce or eliminate the image distortion sometimes caused by eyeglasses.