eyestone
Eye"stone`, n. 1. A small, lenticular, calcareous body, esp. an operculum of a small shell of the family Tubinid, used to remove a foreign sub stance from the eye. It is rut into the inner corner of the eye under the lid, and allowed to work its way out at the outer corner, bringing with the substance. 2. (Min.) Defn: Eye agate. See under Eye.