Bitot's spots are the buildup of keratin located superficially in the conjunctiva of human's eyes.

[2] In ancient Egypt, this was treated with animal liver, which is where vitamin A is stored.

[3] A major cause of Bitot's spots is vitamin A deficiency (VAD).

[4] Rarely, pellagra due to deficiency of vitamin B3 (niacin) may also cause Bitot's spots.

[7] Bitot's spots non-responsive to vitamin A therapy may be removed surgically.