Corneal Ulcers and Contact Lenses: Risks, Symptoms, and When to Seek Emergency Care

Imagine waking up with your eye burning like it’s full of sand, light feels like a knife, and your vision is suddenly blurry. You’ve been wearing your contact lenses for days-maybe even slept in them once or twice. You think it’s just dryness or fatigue. But it’s not. It could be a corneal ulcer, and every hour you wait makes it worse.

A corneal ulcer is an open sore on the clear front surface of your eye. It’s not a scratch. It’s tissue loss. And it’s often caused by infection. While contact lenses are safe for millions, they’re also the leading cause of this serious eye condition. If you wear contacts, you need to know the signs, the risks, and what to do before it’s too late.

Why Contact Lenses Put You at Risk

Over 85 million people worldwide wear contact lenses. Most do it safely. But even a small mistake can turn routine use into a medical emergency. The biggest danger isn’t the lens itself-it’s what happens when you wear it longer than you should, clean it wrong, or expose it to water.

When you wear contacts, especially overnight, you’re blocking oxygen from reaching your cornea. That’s bad enough. But worse, bacteria, fungi, or even tiny parasites like Acanthamoeba can get trapped under the lens. These germs come from your fingers, your tap water, your shower, or even a bottle of expired solution. Once they’re under the lens, they multiply fast. Your eye can’t fight them off without help.

The numbers are stark. If you wear contacts, you’re about 10 times more likely to get a corneal ulcer than someone who doesn’t. If you sleep in them? That risk jumps to 100 times higher. Extended-wear soft lenses are the worst offenders. The FDA warns these lenses can lead to blindness if infections aren’t caught early.

What the Symptoms Really Look Like

People often ignore early signs. They think their eyes are just tired. But corneal ulcers don’t get better on their own. Here’s what to watch for:

• Severe eye pain-like something’s digging into your eye
• Redness that won’t go away, even after removing lenses
• Blurry or hazy vision, like looking through fog
• White or gray spot on the clear part of your eye (you might not see it yourself, but others might)
• Extreme sensitivity to light-even turning on a lamp feels painful
• Excessive tearing or thick, yellowish discharge
• Feeling like there’s still grit in your eye, even after removing lenses

If you have even one of these symptoms and you wear contacts, stop wearing them immediately. Don’t wait. Don’t try to flush it out with water. Don’t reach for over-the-counter drops. This isn’t pink eye. This is an emergency.

How Doctors Diagnose a Corneal Ulcer

Eye doctors don’t guess. They test. If you show up with these symptoms, your eye care provider will run a few key tests:

• Fluorescein staining: A harmless orange dye is dropped in your eye. Under blue light, any damaged areas glow green. It shows exactly where the ulcer is.
• Slit-lamp exam: A high-powered microscope lets the doctor zoom in on your cornea, seeing the depth and shape of the sore.
• Corneal scraping: If the ulcer looks serious, they’ll gently take a tiny sample of the infected tissue. This tells them if it’s bacteria, fungus, or a virus.
• Visual acuity test: They’ll check how well you can see-before and after treatment-to track progress.

Newer tools are helping too. Some clinics now use digital imaging to capture photos of the ulcer and compare them over time. This helps catch changes faster, especially in the first 24 hours when treatment is most critical.

What Happens If You Wait

Time is vision. Every day you delay treatment increases the chance of permanent damage.

Corneal ulcers can scar your cornea. That scar doesn’t heal. It stays. And if it’s in the center of your vision, you’ll have a permanent blind spot. In worse cases, the infection eats through the cornea and can cause your eye to collapse. That’s when you need a corneal transplant-surgery to replace your entire front eye surface.

Bacterial ulcers are the most common and can spread fast. Fungal ulcers are rarer but harder to treat. They often come from contaminated water-like swimming or showering in contacts. Acanthamoeba, a parasite found in tap water, is especially dangerous. It’s resistant to most antibiotics and can linger for months.

And here’s something many don’t realize: Steroid eye drops, which help with inflammation, can make ulcers worse if used without knowing the cause. If you’ve been given steroids for “red eye” in the past, don’t use them again without a doctor’s order. They can hide the infection while it eats your eye.

Treatment: Fast, Aggressive, and Personalized

There’s no one-size-fits-all fix. Treatment depends on what’s causing the ulcer.

• Bacterial ulcers: Treated with strong antibiotic eye drops-usually fluoroquinolones like moxifloxacin or gatifloxacin. These are applied every hour at first, then tapered as healing begins.
• Viral ulcers: Caused by herpes simplex virus. Treated with antiviral drops like acyclovir or ganciclovir. Recurrence is common, so long-term management is often needed.
• Fungal ulcers: Require antifungal drops like natamycin or voriconazole. These are harder to find, harder to use, and take weeks to work.
• Severe cases: If the ulcer is larger than 2mm, close to the center of your vision, or getting worse after 48 hours of treatment, you’ll likely need hospital care. Some patients need IV antibiotics or surgery.

Don’t expect quick results. Healing takes days to weeks. You’ll need daily check-ups. And you must stop wearing contacts-ever-until your doctor says it’s safe. Even then, many people never wear them again.

How to Prevent a Corneal Ulcer for Good

The best treatment is prevention. And it’s simple-if you’re willing to be strict.

• Never sleep in your contacts. Not even for an hour. Not even if they’re labeled “extended wear.” The 100x risk isn’t a myth-it’s data.
• Never expose lenses to water. No swimming. No showering. No rinsing lenses with tap water. Use only sterile solution. Even distilled water can carry Acanthamoeba.
• Wash your hands before touching lenses. Soap and water. Dry with a lint-free towel. Don’t use hand sanitizer-it doesn’t kill all germs.
• Replace lenses on schedule. Daily disposables are safest. If you use monthly lenses, toss them after 30 days-even if they look fine.
• Use only recommended solutions. Never mix brands. Never reuse solution. Always clean the case and let it air-dry upside down.
• Give your eyes a break. Wear glasses at least one day a week. Let your cornea breathe.

The FDA and major eye groups agree: Proper hygiene reduces risk by over 90%. It’s not about being paranoid. It’s about being smart.

When to Go to the Emergency Eye Clinic

If you have pain, redness, or vision changes and you wear contacts-go now. Don’t wait for your regular appointment. Don’t call your GP. Go to an eye specialist or urgent eye clinic.

Many hospitals have dedicated ophthalmology emergency services. In Sydney, clinics like the Sydney Eye Hospital and private ophthalmology centers offer same-day urgent care for corneal issues. Time matters. The sooner you start treatment, the less likely you’ll lose vision.

And if you’ve ever had a corneal ulcer before? You’re at higher risk for another. Be extra careful. Keep your lens case, solution, and glasses ready. Don’t wait for symptoms to get bad.

Corneal ulcers are rare-but they’re devastating. And they’re almost always preventable. Your eyes don’t get a second chance. Treat them like the delicate, irreplaceable organs they are.