The conjunctiva may have a grayish or blackish color if certain conditions are present.
The discoloration may affect one or both eyes.
Black discoloration of the conjunctiva may occur with:
(1) silver exposure (argyrosis)
(2) gold exposure (chrysiasis)
(3) drugs (atabrine, arsenicals)
(4) chemicals (phenols, nitrochlorobenzene)
(5) mascara
