If you get red eyes, it must be allergy of your eyes. You know, the water in pool is not as clearly as we see. And i have such experiences. But my red eyes recovered after a good sleep through one night. If your eyes still in red eyes the next day, you may have to use some anti-inflammation eye drops. If you get your eyes injuries by accidents, you'd better get your eyes checked from eye doctor and ask her/his advices.
Red eyes are medically called acute conjunctivitis. In general, it is virus infection and also complicated with bacterial infection. You can have an anti-virus and anti-bacterial treatment, such as using chloramphenicol eye drops and acyclovir eye drops, you can also use normal saline to wash your eyes. The diseased period is 10~15 days. When you go to swimming pool, you can wear swimming goggles to protect your eyes. You'd better go to the hospital to have a treatment, and take rest, not rub your eyes.
Generally, swimming is the best choice of sports that people prefer in summer. It's not only can make people feel comfortable in hot summer but also keep healthy. Normally the swimming pool's water is cleaned by bleaching powder to decrease infectious disease. However, some people would get red eyes after swimming. One reason that is the bleaching powder would irritate people's eyes lightly. It would disappear after a few minutes or hours without any treatment. If this situation lasts for 1 to 2 days, you had better to drop the antiviral eye drop, such as Chloramphenicol Eye Drops. In order to avoid and decrease the risk of red eyes, you had better take a shower immediately after swimming if it's possible. And closing eyes or wearing a goggle when diving.