When the head of the CDC's healthy swimming program shared some insight into swimming pools, he opened a lot of eyes.

This campaign shows the smell of what many people think is "chlorine," is actually the smell of chemicals as the chlorine mixes with pee, poop, sweat, and dirt.

Yuck, and the eyes can show it.

"It causes extreme dryness to the eyes, and also the chemicals cause a chemical allergy to the eyes,” says optometrist, Mel Gehrig and he sees lots of red eyes this time of year, but it's not always the pool to blame.

"The primary two causes of red eyes most of the time and more during the summer is dry eyes and allergy eyes,” says Gehrig.

Gehrig says we have allergens year-round including the middle of the summer.

"It usually comes in three to four times. Every time we see a change in leaves and a new growing time. October is a bad time. June is a bad time, May and June is a bad time,” says Gehrig.

So, back to the pool water, how can you know that it's not going to burn your eyes or turn them red?

The CDC says healthy pools and water parks don't have a strong chemical smell.

And Gehrig says he trusts that if PH and disinfectant levels are appropriate, the pee and poo chemical mix won't be problematic!

But, if you are going swimming, add goggles to your swimming attire, and Gehrig says artificial tears with lubrication can ease any allergic irritation.

The CDC recommends you ask to see a pool's inspection results if you are concerned about its safety.

If you own a pool, use test strips to check chemical levels.

And if you have a child in a swim diaper or swim pants, be aware that those do NOT stop germs from getting into the water and probably aren’t appropriate in a swimming pool.