Corneal Ulcers from Contact Lenses: Risks, Signs, and What to Do Immediately

A corneal ulcer isn’t just a scratch-it’s an open wound on the clear front surface of your eye. And if you wear contact lenses, you’re at risk. Every year, thousands of people end up in emergency eye clinics because they ignored early warning signs. What starts as mild redness or blurry vision can turn into permanent vision loss in just days. The good news? Most corneal ulcers are preventable. The bad news? They don’t wait for convenient hours to develop.

What Exactly Is a Corneal Ulcer?

The cornea is your eye’s clear, protective dome. When it gets damaged and infected, it can develop an open sore-a corneal ulcer. This isn’t the same as a simple scratch (called a corneal abrasion), which usually heals on its own. A corneal ulcer means tissue is actively breaking down. It’s often caused by bacteria, fungi, or even tiny parasites like Acanthamoeba getting trapped under your contact lens.

According to the FDA, corneal ulcers are one of the most serious risks tied to contact lens use. They can lead to scarring, perforation of the cornea, and even blindness if not treated fast. About 85 million people worldwide wear contact lenses, and while most use them safely, the consequences of even one mistake can be life-changing.

Why Contact Lenses Increase Your Risk

Wearing contact lenses doesn’t automatically mean you’ll get an ulcer. But it does change the game. Here’s how:

• Blocked oxygen: Your cornea needs oxygen to stay healthy. When you wear lenses-especially overnight-they act like a barrier, starving the surface.
• Bacteria buildup: Dirt, proteins, and microbes from your fingers, tap water, or dirty solution get trapped under the lens. Even a clean-looking lens can harbor harmful organisms.
• Extended wear: Sleeping in contacts, even ones labeled "extended wear," raises your risk 100 times compared to someone who removes them nightly.
• Scratched lenses: A tiny tear in your lens can scrape your cornea, giving bacteria a direct path inside.

Soft lenses worn overnight carry the highest risk. Studies show contact lens wearers are about 10 times more likely to get a corneal ulcer than non-wearers. That number jumps dramatically if you wear them while swimming, showering, or sleeping.

Warning Signs You Can’t Ignore

Corneal ulcers don’t always start with intense pain. That’s why people delay care-and why things get worse fast.

Look out for these symptoms:

• Blurry or hazy vision that doesn’t clear up
• Severe eye pain, even when you’re not touching it
• Red, bloodshot eyes that won’t improve
• White or gray spot on the clear part of your eye (visible in the mirror)
• Excessive tearing or thick discharge
• Extreme sensitivity to light-you might squint even in normal indoor lighting

If you’re wearing contacts and notice even one of these, stop wearing them immediately. Don’t wait to see if it gets better. Don’t try to rinse it out with water. Don’t use leftover eye drops from last year. This isn’t a "wait and see" situation.

How Doctors Diagnose It

If you go to an eye specialist with these symptoms, they won’t just glance at your eye. They’ll run specific tests:

• Fluorescein staining: A yellow dye is put in your eye. Under blue light, any damaged areas glow green, showing the exact size and shape of the ulcer.
• Slit-lamp exam: A high-powered microscope lets the doctor see deep into your cornea, checking for infection depth and signs of spreading.
• Corneal scraping: In serious cases, they gently take a tiny sample from the ulcer to test for bacteria, fungi, or parasites. This tells them exactly which drug to use.
• Visual acuity test: They’ll check how well you can see to track changes over time.

Recent advances in imaging now let some clinics use digital photos of the cornea to spot early signs of infection faster than ever before. But none of this replaces the need for prompt, in-person evaluation.

Treatment: Speed Is Everything

There’s no time to waste. The longer a corneal ulcer goes untreated, the more likely it is to scar your vision permanently.

Doctors start treatment immediately-even before they know the exact cause. For most cases, that means fluoroquinolone antibiotic eye drops. These are broad-spectrum and effective against common bacteria like Pseudomonas and Staphylococcus, which are the most frequent culprits in contact lens wearers.

If the ulcer is large (over 2 mm), close to your pupil, or getting worse after 48 hours, it’s considered sight-threatening. That means they’ll take a scraping right away to culture the pathogen. Then they’ll switch to targeted treatment:

• Bacterial: Antibiotics (fluoroquinolones like moxifloxacin or gatifloxacin)
• Viral: Antiviral drops like acyclovir (often from herpes simplex virus)
• Fungal: Special antifungal drops like natamycin or voriconazole
• Parasitic (Acanthamoeba): Requires long-term, aggressive treatment with specific antimicrobial agents

Some patients are tempted to use steroid eye drops to reduce redness or swelling. But steroids can make infections worse-especially if the cause isn’t known. Only use them if your doctor specifically prescribes them and monitors you closely.

In the worst cases, where the cornea is severely scarred or perforated, a corneal transplant may be the only way to restore vision.

How to Prevent a Corneal Ulcer

The best treatment is prevention. Here’s what actually works:

• Never sleep in your contacts-even if they’re labeled "extended wear." The 100x risk increase isn’t a myth.
• Wash your hands with soap and dry them completely before touching your lenses.
• Use only recommended solutions. Never use tap water, saliva, or homemade saline to clean or store lenses.
• Avoid water. Don’t swim, shower, or use hot tubs while wearing contacts. Water carries dangerous microbes like Acanthamoeba.
• Replace lenses on schedule. Don’t stretch out daily, weekly, or monthly lenses. Buildup happens faster than you think.
• Replace your case every 3 months. Clean it daily with solution-not water-and let it air-dry upside down.
• Give your eyes a break. Wear glasses at least one day a week, especially if you’re on screens all day.
• Don’t wear lenses if your eyes are irritated. Redness, dryness, or discomfort are signals to stop.

Even with perfect hygiene, accidents happen. But following these steps cuts your risk by more than 90%.

What to Do Right Now

If you’re wearing contacts and have any of the symptoms listed above:

1. Remove your lenses immediately.
2. Do NOT rinse your eyes with water or try to flush them out.
3. Do NOT use old or over-the-counter eye drops.
4. Call your eye doctor right away. If it’s after hours, go to an urgent eye clinic or emergency room.
5. Bring your lens case and solution with you-it helps the doctor identify possible contamination.

There’s no substitute for professional care. Delaying by even 24 hours can mean the difference between full recovery and permanent vision loss.

Final Reality Check

Contact lenses are convenient. They’re safe-when used correctly. But they’re not risk-free. The statistics don’t lie: overnight wear is the biggest red flag. Ignoring early symptoms is the second.

There’s no shame in needing glasses instead of contacts. There’s no pride in pushing through eye pain. Your vision isn’t something you can afford to gamble with.

If you’ve ever thought, "It’s probably just dryness," or "I’ll sleep in them just this once," that’s the moment to change your habits. Because corneal ulcers don’t wait. And neither should you.