Why do our eyes turn red in the swimming pool?

Choloramine:

Normally pool water is treated with chlorine which is a disinfectant that kills germs in the water. That can't turn our eyes red. Normally the pool water contains urine and sweat in it. They contain nitrogenous urea in it. These urea(amine) reacts with chlorine forms chloramine. If the pools are not regularly cleaned, then the chloramine can irritate our eyes and making them red. Also these chloramines can evaporate in air. When we inhale these air for long time, it can cause asthma.