an eye disease that involves the clouding or opacification of the natural lens of the eye
"After his routine checkup, the doctor confirmed that my father's vision loss was caused by cataracts and recommended surgery to replace the cloudy lens."
a large waterfall; violent rush of water over a precipice
"The ancient legend describes how the great cataract at Niagara roars so loudly that it drowns out all other sounds."
A waterspout
"The storm created a terrifying cataract of water that swept across the valley floor."