Shingles, also known as zoster, herpes zoster, or zona, is a viral disease characterized by a painful skin rash with blisters involving a limited area. Typically the rash occurs on either the left or right of the body or face in a single stripe. Two to four days before the rash occurs there may be pain or tingling in the area. Otherwise there are typically few symptoms. The rash usually heals within two to four weeks; however, some people develop ongoing nerve pain which may last for months or years, a condition called postherpetic neuralgia. In those with poor immune function the rash may occur widely. If the rash involves the eye, vision loss may occur.