A spot on the eye can signify two things: either a spot visible to the patient, corresponding in which case to a scotoma
. Or it can be a spot visible to another person, located on the eye's conjunctiva (the white part). A scotoma is a condition affecting the vision, where there is a blind-spot in the eye, in which case it is called a negative scotoma, or a black spot or filament-shaped black-out, in which case it is called a positive scotoma. When there is a spot on the conjunctiva, the patient is usually unaware, except on looking in the mirror. The spots can look yellow, thus the result of vitamin A deficiency
. When then are red, it can be a sign of conjunctivitis
, but how they look is usually an exaggeration of blood vessel visibility than real spots. When a red spot takes the form of a level-marker at the base of the eye, it signifies a conjunctival hemorrhage, which leads to no problems and disappears of its own accord.