Eye examinations performed on 50 subjects immediately before and after swimming in a chlorinated pool showed that 34 subjects (68%) saw rainbows and/or halos around lights after swimming, a symptom indicating the presence of corneal edema. Forty-seven subjects (94%) had corneal epithelial erosions in a punctate or linear pattern demonstrated by fluorescein staining on slit-lamp examination. No subject experienced a measurable decrease in visual acuity.