“Chlorine turns your eyes red in swimming pools”

That stinging, reddening sensation in your eyes after a dip in the swimming pool is a familiar experience for many, and the immediate culprit is often assumed to be the chlorine itself. This widespread belief has become deeply ingrained in pool lore, with swimmers often citing the chemical as the sole reason for their discomfort. However, the true cause of that irritation is a bit more complex than just the disinfectant doing its job.

The real culprits behind red, itchy eyes are not chlorine alone, but rather chemical compounds called chloramines. These form when chlorine, which is added to kill germs and keep the water clean, reacts with organic materials introduced into the pool by swimmers. These contaminants include sweat, body oils, and, yes, even urine. When chlorine combines with these substances, it creates chloramines, and it is these byproducts that are the primary source of the unpleasant burning and redness swimmers often experience.

The misconception persists largely because chlorine has a distinct smell and is known as a powerful chemical, making it an easy target for blame. Many people also associate a strong "chlorine" smell with a clean pool, when in fact, a very strong chemical odor often indicates a high concentration of chloramines, signaling that the pool actually needs more, not less, maintenance. A properly maintained pool with balanced chemical levels and fewer contaminants will have minimal chloramines and, consequently, will cause significantly less eye irritation.