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:
- Remove your lenses immediately.
- Do NOT rinse your eyes with water or try to flush them out.
- Do NOT use old or over-the-counter eye drops.
- Call your eye doctor right away. If it’s after hours, go to an urgent eye clinic or emergency room.
- 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.
Kimberley Chronicle
November 24, 2025 AT 22:38Interesting breakdown-especially the part about Acanthamoeba in tap water. I work in ocular microbiology, and we see this way more than people realize. The real kicker? Most patients think their lens case is "clean" because it doesn’t look dirty. Spoiler: biofilm doesn’t have a visual cue. Replace your case every 90 days, even if you "clean it daily." And please, for the love of corneal integrity, stop using saliva to wet your lenses. I’ve seen cases where people did this after forgetting their solution on a hike. One. Single. Drop. And boom-parasitic ulcer. Don’t be that person.
Arup Kuri
November 26, 2025 AT 16:02They want you to think this is about hygiene but its really about control the lens companies make you buy new ones every month so they can profit the doctors profit too from all the emergency visits if you just wore glasses like normal people youd be fine why do you need to see 20 feet away without glasses anyway
Roscoe Howard
November 27, 2025 AT 03:32While I appreciate the clinical precision of this post, I must emphasize that the statistical framing is dangerously incomplete. The FDA’s data on corneal ulcers fails to account for cultural hygiene variance-particularly in developing nations where waterborne pathogens are endemic. The real issue isn't lens wear-it’s the absence of infrastructure. In the United States, where we have access to sterile saline and regulated pharmaceuticals, the risk is negligible if protocols are followed. The real epidemic is not in lens wear-it’s in the failure of public health education to differentiate between negligence and systemic failure. We must stop blaming individuals and start addressing global disparities in ocular care access.
Elise Lakey
November 27, 2025 AT 15:58Thank you for this. I’ve been wearing contacts for 12 years and never knew about the 100x risk with overnight wear. I stopped sleeping in them last month after reading this. My eyes feel better already. Also-replaced my case today. I’m gonna start wearing glasses on weekends. Small changes, big difference.
Ellen Sales
November 28, 2025 AT 22:55Okay but can we talk about how the entire contact lens industry is built on fear of glasses?? Like, I get it, you want to look "natural" without frames-but at what cost?? Your cornea is not a vending machine that dispenses clear vision on demand. And the fact that we’re told to "just replace your case every 3 months" while the packaging says "up to 30 days" and the solution bottle says "use within 90 days" is a total marketing trap. Also-why are there no FDA-mandated warning labels on lens boxes that say "SLEEPING IN THESE MAY CAUSE BLINDNESS" in 72-point bold font?? I’m not even mad, I’m just disappointed. 🥺👁️🗨️💔
giselle kate
November 29, 2025 AT 04:28These so-called "experts" are just pushing fear to sell drops and surgeries. In China and Japan, people wear contacts 16 hours a day and sleep in them and they’re fine. The US medical system is just profit-driven. You don’t need all these tests and antibiotics. Just use salt water. I’ve done it for years. No problems. The real threat is the FDA and Big Pharma controlling your vision. Wake up.
Shirou Spade
November 29, 2025 AT 07:10There’s something deeply human in how we treat our bodies like machines we can optimize. We wear lenses to see better, to appear more attractive, to fit in-but we forget the eye is not a camera lens. It’s a living tissue, breathing, pulsing, sensing. To treat it as disposable is to lose touch with the fragility of being alive. The ulcer isn’t a failure of hygiene-it’s a failure of reverence. We’ve normalized risk because convenience is the new god. Maybe the real question isn’t how to prevent ulcers, but why we’ve stopped fearing the cost of our choices.
Ellen Sales
November 30, 2025 AT 05:16Elise Lakey-YES. I did the same thing. I wore glasses for a whole week and realized I didn’t miss my contacts at all. I even liked how I looked in them. Who knew? Also-my dry eyes? Gone. I think the lens industry doesn’t want us to know how much better we feel without them. I’m never going back. 🙌👁️🗨️✨