The discoloration may affect one or both eyes. It may be focal or diffuse.
Diffuse brown coloration:
(1) alkaptornuria
(2) drugs (phenothiazine, anilquinoline combinations, sympathomimetics)
(3) chemicals (aniline dyes, bromide, phenol derivatives, chromates, arsenic)
(4) melanosis of Addison’s disease
(5) congenital melanosis
(6) melanosis following radiation exposure
(7) melanosis following chronic conjunctivitis
(8) melanosis associated with keratomalacia
Localized or diffuse:
(1) subconjunctival hemorrhage (may show fine brown spots)
(2) pigmented limbal ring (senile, post-traumatic, etc)
(3) melanosis oculi
(4) nevus of Ota
(5) melanocytic nevus
(6) malignant melanoma
