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

Every year, millions of people wear contact lenses without a second thought. They’re convenient, discreet, and for most, safe. But if you wear contacts-especially overnight-you’re taking a risk most people don’t even know about. Corneal ulcers are one of the most dangerous complications, and they can blind you in days if ignored.

What Exactly Is a Corneal Ulcer?

A corneal ulcer isn’t just a scratch or irritation. It’s an open sore on the clear front surface of your eye-the cornea. Think of it like a deep wound on your skin, but inside your eye. This isn’t something that heals on its own. It’s caused by infection, usually bacteria, fungi, or even a tiny amoeba called Acanthamoeba, that gets trapped under your contact lens and starts eating away at the corneal tissue.

The difference between a corneal abrasion and a corneal ulcer matters. An abrasion is a surface scratch. It’s painful, but it usually heals in a day or two. A corneal ulcer? It’s tissue loss. It can spread. It can scar. And if it reaches the center of your cornea, your vision could be permanently damaged.

Why Contact Lenses Are the Top Culprit

You’re about 10 times more likely to get a corneal ulcer if you wear contacts than if you don’t. That number jumps to 100 times higher if you sleep in them. That’s not a typo. Sleeping in contacts cuts off oxygen to your cornea, creates a warm, moist pocket where germs thrive, and traps dirt, bacteria, and even saliva from your pillow under the lens.

Soft contact lenses, especially extended-wear types designed for overnight use, are the biggest offenders. Even if you clean them perfectly, bacteria from your fingers during insertion can get under the lens. Water is another silent killer. Showering, swimming, or even splashing your face with water while wearing contacts can introduce dangerous microbes. The FDA has issued multiple warnings about specific lens solutions linked to fungal and amoebic infections.

Other risk factors include:

• Wearing lenses past their replacement date
• Using tap water or saliva to clean lenses
• Scratched or damaged lenses
• Having dry eyes, blepharitis, or conditions like Bell’s palsy that prevent full eyelid closure
• Using steroid eye drops without medical supervision

Symptoms You Can’t Ignore

If you wear contacts and notice any of these, stop wearing them immediately and call your eye doctor-today:

• Severe eye pain, worse than a headache
• Red, bloodshot eye that won’t improve
• Blurry, hazy, or cloudy vision
• White or gray spot on the clear part of your eye
• Excessive tearing or pus-like discharge
• Extreme sensitivity to light-even turning on a lamp feels unbearable
• Feeling like something’s stuck in your eye, even when there’s nothing there

These symptoms don’t wait. They don’t get better with rest or eye drops you bought online. Delaying care by even 24 hours can mean the difference between full recovery and permanent vision loss.

How Doctors Diagnose a Corneal Ulcer

Your eye doctor won’t just look at your eye. They’ll use specialized tools to see what’s happening beneath the surface.

First, they’ll put a yellow dye called fluorescein in your eye. Under blue light, any damaged areas on the cornea glow green, making the ulcer visible. Then they’ll use a slit-lamp-a high-powered microscope with a bright light-to examine the size, depth, and location of the sore.

If it looks serious, they’ll gently scrape a tiny bit of tissue from the ulcer and send it to a lab. This culture test tells them exactly what’s causing the infection: bacteria? fungus? amoeba? That’s critical because each needs a different treatment.

They’ll also check your vision, measure the curvature of your cornea, and monitor for signs the infection is spreading.

Treatment: Speed Is Everything

There’s no time to wait. Treatment starts the moment the ulcer is suspected-even before test results come back.

For most bacterial ulcers, doctors prescribe strong antibiotic eye drops-usually fluoroquinolones like ciprofloxacin or moxifloxacin. You’ll need to use them every hour or two, day and night, for the first few days. That’s not a suggestion. That’s the protocol.

If it’s a fungal infection, you’ll need antifungal drops, which are harder to get and take longer to work. Viral ulcers, often from herpes, are treated with antivirals like acyclovir.

In severe cases-where the ulcer is larger than 2 mm, close to the center of your vision, or getting worse after 48 hours of treatment-you might need hospitalization. Some patients require surgery to remove infected tissue or even a corneal transplant if the damage is too deep.

Steroid drops? They’re sometimes used to reduce swelling, but only under strict supervision. Using them without knowing the cause of the infection can make things worse-fast.

Prevention: The Only Real Safety Net

The best treatment for a corneal ulcer is not having one in the first place. Here’s what actually works:

• Never sleep in your contacts. Even if they’re labeled “extended wear,” your eyes don’t get enough oxygen when your eyelids are closed. The 100x risk increase isn’t hype-it’s science.
• Replace lenses on schedule. Daily disposables are safest. If you use monthly lenses, throw them out after 30 days, no exceptions.
• Wash your hands before touching your lenses. Soap and water. Dry with a lint-free towel. Don’t use paper towels-they shed fibers.
• Use only the solution your doctor recommends. Never reuse old solution. Never top off the case. Never use water, saliva, or homemade saline.
• Take your lenses out before swimming, showering, or hot tubbing. Water is not your friend.
• Give your eyes a break. Wear glasses at least one day a week. Let your cornea breathe.
• Inspect your lenses daily. If you see a scratch, tear, or buildup you can’t clean off, toss it.

What to Do Right Now

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

1. Take your lenses out immediately.
2. Do NOT rub your eye.
3. Do NOT use over-the-counter eye drops unless they’re preservative-free artificial tears.
4. Call your eye doctor right away. If you can’t reach them, go to an emergency room or urgent eye care center.
5. Bring your lens case and solution with you. The doctor may need to test them.

Why This Isn’t Just a Minor Issue

The FDA calls corneal ulcers a “serious hazard” that can lead to blindness. And it’s not rare. With over 85 million contact lens wearers worldwide, thousands develop ulcers every year. Many of them didn’t think they were at risk. They cleaned their lenses. They didn’t sleep in them-every night. But one missed step, one splash of water, one extra day of wear, and it’s enough.

Technology is improving. Newer lens materials allow more oxygen. Diagnostic imaging helps catch ulcers earlier. But none of that replaces good habits. No lens is foolproof. No solution is magic. Your eye’s health depends on you.

What Comes After Recovery

Even if your ulcer heals completely, you’ll need follow-up visits. Scarring can develop weeks later. Your vision might not return to 100%. Some people can’t wear contacts again. Others need to switch to daily disposables and follow stricter rules.

The goal isn’t just to heal the ulcer. It’s to prevent it from ever coming back.