Swimming and Your Eyes: Chlorine, Goggles, Contacts and Infections

Swimming is one of the best forms of exercise: low impact, good for the heart and suitable for almost every age. It does, however, put your eyes in direct contact with water that is never truly sterile. Pool water contains disinfectant by-products; lakes, rivers and the sea contain microorganisms; and tap water used to fill hot tubs and rinse goggles is not free of germs either. Most of the time the result is nothing worse than red, stinging eyes for an hour. Occasionally, especially for contact lens wearers, the consequences can be serious.

This article explains what water does to your eyes, how to choose and use goggles, why contact lenses and swimming are a risky combination, and what to watch for after swimming in open water.

Why pools make your eyes red

Swimming pools are disinfected, usually with chlorine, to kill bacteria and viruses. When chlorine reacts with sweat, urine, skin cells, cosmetics and other substances brought in by swimmers, it forms compounds called chloramines. These are responsible for the strong "pool smell" and are a major cause of eye and respiratory irritation. According to the US Centers for Disease Control and Prevention, a strong chemical smell in an indoor pool usually indicates high chloramine levels, not a well-maintained pool.

Water also washes away the protective tear film that normally coats the eye. Without this oily and watery layer, the corneal surface is exposed and can swell slightly, which may cause temporary blurring and haloes around lights after a long swim. Pool water pH that is too high or too low adds to the stinging.

The symptoms, which typically include redness, stinging, grittiness and mild blur, usually settle within an hour or two. People with dry eye or allergies may notice symptoms lasting longer.

Reducing chlorine irritation

• Wear goggles every time you swim.
• Shower before entering the pool. Fewer contaminants in the water mean fewer chloramines for everyone.
• Rinse your face and closed eyes with clean fresh water after swimming.
• Use preservative-free lubricating drops before and after swimming if your eyes tend to feel dry.
• Avoid rubbing your eyes, which can worsen irritation and transfer germs.
• If a pool consistently causes problems, mention it to the staff; good ventilation and water management reduce chloramines.

Goggles: choosing and using them

Goggles keep water out of your eyes, which reduces irritation and infection risk and makes it easier to see underwater. A good fit matters more than price or brand.

Getting the right fit

1. Without using the strap, press the goggles gently into your eye sockets. A well-fitting pair should stay in place for a few seconds through suction alone.
2. Adjust the nose bridge so the lenses sit centred over your eyes without pressing on the nose.
3. Position the strap at the back of the head, above the ears, tight enough to seal but not so tight that it leaves deep marks or causes headache.
4. Choose a soft silicone gasket if you have sensitive skin.

Racing goggles with small, hard eyecups are designed for streamlining but can press hard on the eyes. For recreational swimming or people with glaucoma, larger mask-style goggles that rest on the bone around the eyes are often more comfortable. Very tight goggles can temporarily raise eye pressure; if you have glaucoma, ask your eye doctor about suitable designs.

Lens tints and coatings

Anti-fog coatings wear off with rubbing. Rinse goggles in fresh water after use, let them air dry and avoid touching the inside of the lenses.

Prescription goggles

If you are short-sighted or long-sighted, swimming without correction can make it hard to see lane lines, clocks or other swimmers. Options include:

• Ready-made corrective goggles with equal power in both lenses, usually for short-sightedness, in common steps. These are inexpensive and work well if both eyes have similar prescriptions and little astigmatism.
• Modular goggles where each eyepiece can be chosen separately, useful when the eyes differ.
• Custom prescription goggles made to your exact prescription, including astigmatism correction, ordered through an optician.
• Bonded goggles where prescription lenses are attached inside standard goggles.

Bring your current prescription when ordering. Our guide on how to read your glasses prescription can help you understand the numbers.

Contact lenses and water: a dangerous combination

Contact lens wearers are the group most at risk of serious eye infection from water. The main concern is Acanthamoeba, a microscopic amoeba found widely in tap water, swimming pools, hot tubs, lakes, rivers and soil. Chlorine levels in pools do not reliably kill it.

In someone not wearing lenses, Acanthamoeba rarely causes problems. A contact lens, however, can trap the organism against the cornea, and small surface abrasions caused by lens wear give it a way in. The resulting infection, Acanthamoeba keratitis, is rare but very painful, difficult to treat, can require months of intensive drops and sometimes leads to scarring, the need for corneal transplant or permanent vision loss. Most cases occur in contact lens wearers. Bacterial infections such as Pseudomonas are also more likely when lenses are exposed to water.

The best option for regular swimmers who need correction is prescription goggles. Some people discuss orthokeratology or refractive surgery with their eye doctor, but these have their own considerations. Read our article on contact lens hygiene mistakes for other habits that reduce infection risk.

Open-water swimming

Lakes, rivers, reservoirs and the sea offer a wonderful swimming experience but are not treated with disinfectant. Water quality varies with weather, season, wildlife, agricultural runoff and sewage overflows.

Eye risks in open water

• Infections: bacteria and viruses in contaminated water can cause conjunctivitis. Acanthamoeba is also found in natural waters.
• Irritation: salt, sand, algae and silt irritate the eye surface.
• UV and glare: sunlight reflects off water, increasing UV exposure and the risk of photokeratitis.
• Cold water: very cold water can cause eye discomfort and reflex watering, and the cold shock response can lead to panic; always enter gradually.

Staying safe

1. Check local water quality information and avoid swimming after heavy rain or when sewage or algae warnings are in place.
2. Wear goggles with UV protection, ideally tinted or polarised for outdoor conditions.
3. Avoid swallowing water and keep your face out of visibly polluted or stagnant water.
4. Shower and rinse your face with clean water afterwards.
5. Do not swim with an open eye wound, recent eye surgery or an active eye infection.

Hot tubs and spas

Warm water in hot tubs encourages bacterial growth, and disinfectant levels can fall quickly with heavy use. Pseudomonas is a known cause of hot tub-related skin rashes and can infect the eyes, particularly in contact lens wearers. Keep your face out of hot tub water, never wear contact lenses in one, and use only well-maintained facilities.

Swimming after eye surgery or with eye conditions

Always follow the specific advice from your surgeon or eye doctor, as recommendations differ by procedure and healing. Our guide to eye surgery options gives more general information.

Children and swimming

Children often swim for long periods and are less likely to keep goggles on. Help them find comfortable goggles that seal well, encourage rinsing afterwards and teach them not to rub their eyes. If a child develops red, sticky eyes after swimming, keep them home from the pool until symptoms settle, and see a doctor if eyelids become swollen or the child has pain or light sensitivity.

When to see a doctor

Mild redness and stinging that disappear within a few hours are normal. See a pharmacist or optometrist if redness lasts more than a day, if eyes become sticky with discharge, or if dryness persists.

Tell the doctor you wear contact lenses and that you have been swimming; this information helps them consider Acanthamoeba and bacterial infections early. Take your lenses and case with you if possible. Early treatment makes a big difference to the outcome. For general advice on recognising emergencies, see our eye emergencies and first aid guide.

With goggles, a fresh-water rinse and a firm rule of no contact lenses in water, you can enjoy pools, lakes and the sea while keeping your eyes healthy.