What Makes Your Eyes Burn in a Pool?

There is confusion about what exactly causes someone’s eyes to burn when swimming in a pool. Most people believe that if their eyes are burning while swimming in a pool, then it is due to the chlorine in the pool. In reality, there are two more common reasons that can cause eye irritation when swimming in a pool.

Improper pH Balance

An improper pH balance in your swimming pool can cause your eyes to burn. The pH of the human eye is 7.4. When the pool’s pH balance is within the 7.2 to 7.8 range, it is more comfortable for the eyes. When the pH is outside this range, your eyes may begin to burn or feel uncomfortable in the pool. A pool maintenance visit can fix imbalanced pool chemistry.

Therefore whenever the pH range is either low (more acidic water) or high (more basic water) then this typically causes discomfort to the human eye. This principle is similar to balancing the pH in baby shampoos to protect the baby’s eyes during bathing.

The Other Common Reason for Stinging Eyes: Too Little Chlorine

People often think it is chlorine that is burning their eyes. But this is inaccurate. The real reason we experience eye irritation is the result of chlorine binding with things like ammonia to create chloramine. Chloramine is what causes eye irritation. Shocking your pool regularly will break apart chloramines building up in your pool and help prevent stinging or burning eyes.

How to Prevent Burning Eyes After Swimming

Over time, free chlorine in your pool turns into combined chlorine. This means it has been locked up by organic waste and contaminants. When this happens, chloramines are produced. (These are also responsible for "chlorine smell" as well as eye irritation). To eliminate this problem you have to add more free chlorine to the water. The goal is to reach breakpoint chlorination by adding the necessary dosage of chlorine to eliminate the combined chlorine in the water so that the free chlorine can effectively do its job and sanitize the water properly.