Why You Shouldn't Swim with Contact Lenses: Risks of Keratitis and Infections, and Safety Tips

An Ophthalmologist's Expert Guide to Safe Summer Workouts

Hello. This is BGN Eye Clinic Jamsil Lotte Tower.

Recently, many people are choosing swimming as their regular workout, alongside gym sessions, Pilates, and golf. Indoor pools are great for year-round, full-body exercise, making them highly popular among professionals and students alike.

However, there is one question that inevitably comes up in the consultation room when discussing swimming:

"Is it okay to wear contact lenses while swimming?"
"It shouldn't be a problem if I just go in the water for a quick dip, right?"

Unfortunately, the definitive answer is absolutely not! Today, we will explain why swimming with contact lenses is highly dangerous and share essential tips to keep your eyes safe.

Why is the Combination of Contact Lenses and Pool Water Dangerous?

Contact lenses are extremely thin pieces of plastic that sit directly on your corneas. This means they are fully exposed to the external environment. Entering a swimming pool or the ocean with them on exposes your eyes to significantly more risks than being bare-eyed.

1. Bacteria and Parasites

While pool water is treated with chlorine, it does not completely eliminate all bacteria and microorganisms. Underwater, a contact lens acts like a 'suction cup.' Bacteria latch onto the lens surface and become trapped between the lens and the eye, prolonging their stay.

Among these threats, Acanthamoeba keratitis is a rare but highly feared condition in ophthalmology. Once infected, treatment is prolonged, and in severe cases, corneal damage can lead to vision loss. Because it is a "low-probability but high-risk" disease, prevention is your absolute best defense.

2. Chlorine and Chemical Irritants

You are likely familiar with the distinct chlorine smell of swimming pools. Even bare eyes can experience redness and stiffness after swimming. With contact lenses, the situation worsens. Because lenses absorb moisture, chlorine and chemicals become trapped in the lens, adhering to the eye longer and causing severe irritation, redness, stinging, and dryness.

3. Lens Damage and Deformation

It is difficult for a lens to stay in place underwater. The water pressure can easily displace or wash away the lens. Furthermore, saltwater can deform the lens material, leading to blurry vision. Even more dangerous is the risk of the lens folding or tearing while in the eye, which can severely scratch the cornea.

Is the Ocean Any Safer?

Occasionally, patients ask, "If the pool is bad, is seawater okay?" Unfortunately, the ocean is not safe either.

• • 1) Salinity and Osmotic Stress: Seawater has a high salinity (about 3.5%), while our tears are low in salt (about 0.9%). When high-salinity water touches the eye, the osmotic difference draws moisture out of the cornea, causing immediate stinging and dryness. Soft lenses dehydrate, shrink, and deform, leading to blurry vision and micro-abrasions from increased friction.
• • 2) Bacteria and Biofilm Risks: Seawater is teeming with microorganisms like amoebas, fungi, and plankton. The lens surface provides a perfect foundation for these microbes to form biofilms. If trapped between the lens and the cornea, the risk of severe infections like keratitis skyrockets.
• • 3) Sand, Microplastics, and Debris: Ocean water carries sand, microplastics, and floating debris. If these particles get behind your lens, they act like sandpaper, scratching your cornea and creating entry points for bacterial infections.
• • 4) Chemical and Pollutant Exposure: Seawater often mixes with sunscreen, body oils, and sometimes pollutants. Lenses absorb these fat-soluble residues, causing discomfort, blurry vision, and allergic reactions.
• • 5) Waves, Water Pressure, and Loss Risks: Strong waves and diving can easily displace, fold, or wash away your lenses. A partially folded lens moving across the eye can cause painful corneal scratches.
• • 6) UV Rays and Glare: The water's surface reflects a high amount of UV rays. Even if your lenses have UV protection, they do not cover the entire eye or eyelids. UV-blocking goggles or sunglasses are essential to prevent photokeratitis.

Conclusion: Both Pools and the Ocean are Dangerous
The combination of osmotic stress, microorganisms, abrasive particles, chemicals, and physical forces creates the worst possible environment for your eyes and lenses. The thought that "just a moment is fine" is incredibly dangerous.

A Real Consultation Case

Recently, a college student visited us after going to a water park with friends during summer vacation. Thinking "it's just playing in the water," she wore her contact lenses all day to avoid blurry vision.

She enjoyed the wave pool, slides, and outdoor pools, but on her way home, her eyes became severely bloodshot and painful. She initially brushed it off, but the next morning, the intense stinging and stiffness persisted even after removing her lenses, prompting her to visit our clinic.

Our examination revealed that her corneas were scratched and accompanied by a bacterial infection. Fortunately, we started treatment immediately, preventing major complications, but she endured significant discomfort for several days during recovery.

Her words in the consultation room still resonate with me:
"I really didn't know it would be this bad. I thought I could just take them out if it got uncomfortable. I will never swim with lenses again."

How to Swim Safely?

To enjoy swimming while protecting your eye health, strictly follow these four principles. They are not just a simple checklist, but scientifically backed methods to safeguard your vision.

1. Never Wear Contact Lenses

Always remove your lenses before entering the water. There are no exceptions, even for daily disposable lenses. Lenses act as a breeding ground for bacteria underwater. Even a 10-minute exposure is enough for bacteria to adhere and significantly increase infection risks.

2. Always Wear Swimming Goggles

Even bare eyes are easily irritated by chlorine, salt, and bacteria. Goggles serve as the minimum protective barrier against these irritants. Prescription goggles are widely available, so if you usually wear lenses, please utilize them.

3. Use Artificial Tears After Swimming

After swimming, your eyes may be dry and retain impurities. Use preservative-free artificial tears to keep your eyes hydrated and gently flush out any remaining debris.

4. Visit an Eye Clinic Immediately if Symptoms Arise

If redness, stinging, pain, or a foreign body sensation persists for more than a day, never ignore it. If bacteria enter through micro-scratches on the cornea, simple redness can quickly escalate into keratitis or a severe infection. Do not neglect your eye health; visit BGN Eye Clinic anytime.

Contact Lenses Are Strictly Prohibited When Swimming!

Your vision is one of your most precious assets. An infection or damage caused by a single contact lens can sometimes lead to lifelong regret. Conversely, changing just one small habit can keep your eyes perfectly safe.

Remember these three things: remove your lenses before entering pools or the ocean, use prescription goggles if you need vision correction, and clean your eyes with artificial tears afterward.

We hope you enjoy refreshing and safe swimming for a long time, viewing the underwater world clearly with healthy eyes. BGN Eye Clinic Jamsil will always be your reliable partner in protecting your vision.