Why does chlorine hurt your eyes?

Answer 1

The real problem with eye irritation in pool water is not its chlorine content, but two other factors. First is water in general. Any kind of water, chlorinated or not, will have the effect of drying our your eyes (that seems counterintuitive, I know, but it is true). This will cause some eye irritation no matter what.

Secondly, the pH value of the water in the pool is the major factor in eye irritation. A well maintained public pool will keep the pH balance as close to 7.4 - 7.6 as it can, as this is close to matching your body's (and your eyes') natural pH balance. Depending on what variety of chlorine the pool uses, it will tend to raise or lower the pH balance of the water and needs to be checked daily and other chemicals added to even out the pH.

A third less common factor is the presence of chloramines. In any swimming pool the chlorine does not always oxidize the organic matter in the pool completely. This residue consists of a whole range of organic compounds, including Ammonia, which can cause eye and skin irritation. Again, counter-intuitively, the solution to eye irritation from this cause is to increase the chlorine levels in the pool to help complete the oxidation process.

I have never heard of any long-term eye damage from recreational swimming. Wash off after every swim session and use eye-drops to make your eyes feel better. If you are swimming competitively or swimming regularly for fitness its a good idea to use swim goggles.

Remember also that sun exposure can cause eye irritation, and with the reflection of sunlight off of water and off of a light colored pool deck you can even sunburn your eyes. It is a good idea to wear UV-rated sunglasses when not in the water.

Source(s):I am a certified Pool Operator and was an Aquatics Facility Manager, Lifeguard & Swim Instructor for many years