Red eyes after a swim? Don't blame chlorine

If you think it’s the chlorine that makes your eyes red in swimming pools, think again.

According to the annual healthy swimming report from the Centers for Disease Control (CDC), swimmer's urine mixed with other chemicals causes your eyes to get red and sting in swimming pools, Today reports.

“It’s not the chlorine itself. It’s the chlorine mixed with poop and sweat and a lot of other things we bring into the water with us,” said Michele Hlavsa, chief of the CDC’s healthy swimming program, to Today.

Hlavsa said the nitrogen in urine “combines with the chlorine and it forms what’s known as chloramine … that causes the red eyes.” Also, beware if the pool you are swimming in has a very strong smell of chlorine. “Healthy pools don’t smell like chemicals,” Today reports.

Most people believe chlorine will help eliminate urine from swimming pools, but Hlavsa told Today the chlorine is busy cleaning E. coli and other potential germs in the water.

“People think waterborne disease is something that happens outside the United Sates. But really, we have plenty of them here,” Hlvasa said to Today.

Hlavsa recommends pool owners to get a pool tester. “You’re looking at both the chlorine level and the pH,” she said to Today. The chlorine level should be “1 to 3 ppm” and the pH level “between 7.2 to 7.8. The pH is important because it determines how effective that chlorine is,” Hlavsa told Today.

The CDC also offers more tips such as showering before getting in the water, and trying not to swallow any pool water.

“We don’t want to scare people away from swimming,” Hlavsa said to Today. “It’s just about doing it in a healthier and safer way.”