I vaguely remember this being a plot point in an episode of 'The Adventures of Pete and Pete'†. I'm sure there are plenty of chemists that have valiantly attempted to find something that could both stay stable in UV-blasted chlorinated water and react with a weak acid to give an absorption in the visible wavelength. . .but that is a very long and hard-to-fulfill wishlist.

Anyway, it's just any sort of amine reacting with chlorine that produces the chloramines that irritate your eyes. Even if nobody urinated in the pool, the sweat people produce would still be able to cause it. Obviously it wouldn't deplete chlorine as quickly, but it isn't that irritation only comes from urine alone.

Further, I'm more worried by this: > "We have a new parasitic germ that has emerged that's immune to chlorine," says Beach. "We've got to keep it out of the pool in the first place. We need additional barriers." - Dr. M Beach, Associate Director at Healthy Water, CDC

† See here: https://youtu.be/xQOePM_ewVM?list=PLBwI3kpp6F3Kk0_jpewLabhLT...