Urine, not just chlorine, causes red eyes in pools

A new cause has emerged for why you might have red and burning eyes when you emerge from a pool — urine.

Many swimmers and mothers have long believed chlorine was to blame. Chlorine, according to the CDC, is one of the most commonly produced chemicals in the U.S. and is often found in swimming pools, drinking water and sewage to kill harmful bacteria.

But the Centers for Disease Control and Prevention say a mixture of urine, sweat and waste in the communal water is the main perpetrator of discomfort to the eyes.

“Irritants in the air at swimming pools are usually the combined chlorine by-products of disinfection. These by-products are the result of chlorine binding with sweat, urine, and other waste from swimmers,” the CDC reports.

Indoor pool waters can cause the most sting. As the concentration of the mixture of chlorine and human excretion builds up in the water, it circulates into the breathing air, leading to the red and burning eyes.

The health organization explained that fresh air can reduce this perennial phenomena in summertime pools.

To limit the amount of irritation to eyes, the CDC suggests that doors and windows around pools should stay open to keep a steady air flow. After getting out of the pool, swimmers are advised to shower and wash away any of the chlorine by-products.

Wearing googles is always a safe bet, too.