cataract Look up cataract at Dictionary.com
1430, from L. cataracta "waterfall," from Gk. katarhaktes "swooping, rushing down," from kata "down" + arhattein "to strike hard." Its alternative sense in L. of "portcullis" was probably passed through M.Fr. to form the Eng. meaning "eye disease" (1547), on the notion of "obstruction."