Swimming in Chlorine: Hard on Your Eyes?
The irritation you may feel during or after swimming in chlorine is called “chemical conjunctivitis”. Such eyesight problems are caused by the chlorine-rich chemicals, including sodium hypochlorite and calcium hypochlorite, used in the treatment of pool water.
Chlorine is used to treat water in swimming pools because it protects against the growth of microbes and bacteria in still pool waters. In a chlorinated pool, between 12 percent and 95 percent of the total chemical content will be chlorine, according to the EPA.
Here’s what swimming in chlorine can do to your vision—and what you can do about it.
How Chlorine Works
The most comfortable pH level for a human body is 7pH. The pH scale, a measure of acidity or alkalinity, ranges from 1 to 14. Any number below 7 indicates an acid; any number above 7 indicates a base.
At 6.5 pH, chlorine can destroy bacteria, but the chlorine effects on skin can be painful. Above 7.8 pH, the chlorine in the pool can’t defend against bacteria. Chlorine affects the pH balance of a pool, which should be between 7.2 and 7.8 pH in order to be effective.
Swimming Underwater in a Chlorinated Pool
When swimming, chlorine in water can affect your vision anytime you open your eyes underwater.
As light travels through water, it bends, creating a natural distortion of vision. Aside from this natural distortion, chlorine can irritate the eyes, making it difficult to see clearly and triggering the impulse to close your eyes.
Any swimming in chlorine can irritate your eyes.
Even if you don’t open your eyes underwater—or go under water at all—chlorine can affect your eyes. When the chemicals in a pool are out of balance, the chemical reactions can release fumes that irritate the eyes. Any chlorinated water that splashes into your eyes can trigger irritation, as well.
Protect Your Vision When Swimming in Chlorine
Here’s how to protect your eyes from chlorine-related irritation:
- Take care of your pool. A perfectly calibrated pool with a pH of 7 will not irritate most human eyes—though there are exceptions. Care for your pool as instructed and test regularly to make sure that chlorine and other chemical levels are within normal limits.
- Limit your exposure. It can be tempting to spend long afternoons in the sun and the water—and there’s a lot to be said for the enjoyment of a pool. If you’re staying for the long haul, minimize your underwater swimming and get out every 20 minutes or so to avoid prolonged irritation.
- Wear goggles. Protective goggles can help protect your eyes as well as improve your underwater vision. Especially if you plan to be in the pool for several hours, goggles can be your key to comfortable vision both during and after your swim.
The irritation brought on by swimming pool chlorine usually corrects itself without any need for treatment. Eyesight problems can be disconcerting and scary for anyone, at any age. Swimming in chlorine can affect your eyes during and after your swim, but it’s unlikely to cause any lasting damage.