Cataract refers to a clouding of the lens of the eye, or of its surrounding transparent membrane, that obstructs the passage of light. Cataract is also used, often in literature, to refer to a waterfall, steep rapids in a river, or to a downpour or flood.

// Cataracts are common but can be corrected with surgery.

// The roaring cataract is one of the park’s most majestic sights.

See the entry >

“I became a grandmother at the beginning of the decade and again at the end. I decided what kind of grandmother I wanted to be. I came to accept my identity as a writer. I retired from teaching after twenty years. I continue to work as a social work consultant. I had cataract surgery and can see better than I have in years.” — Lyn Slater, How to Be Old: Lessons in Living Boldly from the Accidental Icon, 2024

The ocular meaning of cataract that English users are most familiar with is also the oldest. It dates to the 14th century and comes from the Latin word cataracta, meaning “portcullis,” probably because a cataract in one’s eye obstructs vision much like a portcullis’s heavy iron grating obstructs passage into a fortress or castle. Cataracta has another meaning, however—“waterfall”—and that meaning gave English the water-related meanings that came in later centuries. The connection between the two Latin meanings can be seen in katarassein, the Greek source of cataracta. It means “to dash down,” describing the action of both the slamming portcullis and the cascading waterfall.