A<unk>  is an abnormal protrusion of the uveal tissue through a weak point in the eyeball. The protrusion is generally black in colour, due to the inner layers of the eye. It occurs due to weakening of outer layer of eye (cornea or sclera) by an inflammatory or degenerative condition. It may be of five types, depending on the location on the eyeball (bulbus oculi).
Staphyloma
Shiitake mushroom dermatitis
Dermatitis repens
Tinea versicolor
Shingles
Acne necrotica
Streptococcal intertrigo
Keratolysis exfoliativa