pinguecula, very common yellow-white nodule in the conjunctiva at the front of the eye, usually on the side of the cornea near the nose, although it can form on either side of the cornea. The conjunctiva is the mucous membrane that lines the eyelid and extends over part of the surface of the eyeball. Pingueculae occur in elderly persons and are thought to represent degeneration in the conjunctiva as a result of exposure to ultraviolet light. The condition does not usually require medical or surgical treatment, although rare cases of irritation caused by pingueculae can be treated with lubricants.