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

A corneal ulcer isn’t just a sore eye-it’s an open wound on the clear front surface of your eye that can destroy vision in days if ignored. For the 85 million people worldwide who wear contact lenses, this isn’t a rare scare. It’s a real, preventable danger. While most lens wearers never have problems, the moment you sleep in your contacts, skip cleaning them, or swim with them in, you’re gambling with your sight. And if you start feeling intense pain, notice blurry vision, or see a white spot on your eye, corneal ulcer is likely the culprit-and you need help now.

What Exactly Is a Corneal Ulcer?

The cornea is the clear, dome-shaped layer covering your iris and pupil. It’s tough, but not invincible. A corneal ulcer is a break in this surface, usually caused by an infection that eats away at the tissue. It’s not the same as a scratch (called a corneal abrasion), which heals on its own. Ulcers involve actual tissue loss. Left untreated, they can scar the cornea, cause permanent vision loss, or even lead to blindness.

The most common cause? Contact lenses. Not because lenses are bad-but because they create the perfect conditions for infection. When you wear a lens, especially overnight, it blocks oxygen from reaching the cornea. That weakens the eye’s natural defenses. Then, bacteria, fungi, or even tiny parasites like Acanthamoeba get trapped under the lens. They multiply fast. Your eye can’t fight back alone.

Why Contact Lenses Are the #1 Risk Factor

Wearing contacts makes you about 10 times more likely to get a corneal ulcer than someone who doesn’t wear them. But it gets worse. If you sleep in your lenses-even just once-you’re 100 times more likely to develop one. That’s not a typo. Extended-wear soft lenses, marketed as convenient, are the biggest offenders. The FDA explicitly warns that improper contact lens use can lead to blindness.

It’s not just about sleeping in them. Other habits raise your risk:

• Using tap water to rinse or store lenses
• Wearing lenses longer than recommended (monthly, biweekly, daily)
• Not washing hands before touching lenses
• Using expired or non-prescription cleaning solutions
• Wearing lenses while swimming, showering, or in hot tubs
• Using scratched or dirty lenses

Even your eye health matters. If you have dry eyes, blepharitis (eyelid inflammation), or conditions like Bell’s palsy that prevent full eyelid closure, your cornea is more vulnerable. Steroid eye drops, sometimes used for redness or allergies, can make infections worse by suppressing your immune response.

Red Flags: When Your Eye Is Screaming for Help

Corneal ulcers don’t sneak up. They hit hard and fast. If you’re wearing contacts and notice any of these symptoms, stop wearing your lenses immediately and call your eye doctor-or go to an emergency clinic.

• Severe eye pain, even when you’re not touching it
• Blurry, hazy, or foggy vision
• Red, bloodshot eyes that won’t improve
• White or grayish spot on the cornea (visible in the mirror)
• Excessive tearing or pus-like discharge
• Extreme sensitivity to light (photophobia)
• Feeling like something’s stuck in your eye-even when there’s nothing there

Some people mistake these for a bad case of dry eyes or pink eye. Don’t. Pain that wakes you up at night? Vision changes? That’s not a minor irritation. That’s an emergency.

How Doctors Diagnose a Corneal Ulcer

If you show up with these symptoms, your eye doctor won’t guess. They’ll test. The first step is usually fluorescein staining: a yellow dye is dropped into your eye, and under blue light, any damaged areas glow green. That’s how they see the ulcer’s size and shape.

Then comes the slit-lamp exam-a powerful microscope that lets them zoom in on every layer of your cornea. If the ulcer is large or deep, they’ll scrape a tiny sample from the surface. That sample goes to a lab to find out what’s causing the infection: bacteria? fungus? Acanthamoeba? The answer changes everything.

They’ll also check your vision with an eye chart and measure your corneal curvature. Newer tools now use high-resolution photos and AI to spot early signs of infection before it’s obvious to the naked eye. But none of this replaces a hands-on exam.

How Corneal Ulcers Are Treated

Time is everything. The longer you wait, the more damage the infection does. Treatment starts immediately-often before the lab 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 several days. If the ulcer is near the center of your cornea (the visual axis) or larger than 2 mm, it’s considered sight-threatening. In those cases, you’ll likely be referred to a corneal specialist right away.

If it’s viral, antiviral drops like acyclovir are used. Fungal ulcers need antifungal medications, which are harder to treat and take weeks. In rare cases, if the infection destroys too much tissue, a corneal transplant becomes the only option to restore vision.

Here’s what you should never do: use over-the-counter redness drops, steroid eye drops without a prescription, or home remedies like honey or tea bags. These can make things worse. Only use what your doctor prescribes.

Prevention: The Only Real Cure

The best treatment for a corneal ulcer is never having one. Here’s what actually works:

• Never sleep in your lenses. Even if they’re labeled “extended wear,” the risk isn’t worth it.
• Replace lenses on schedule. Don’t stretch monthly lenses into month two.
• Wash your hands before touching your eyes or lenses.
• Use only recommended solutions. Never use water, saliva, or homemade mixes.
• Take lenses out before swimming, showering, or using a hot tub. Water carries dangerous microbes.
• Store lenses in fresh solution every night. Never top off old solution.
• Give your eyes a break. Wear glasses at least one day a week.
• Replace your lens case every 3 months. Bacteria build up in old cases.

And if you’re ever unsure-skip the lens. Wear glasses. It’s not inconvenient. It’s safer.

What Happens If You Ignore It?

Some people think, “I’ll wait a day to see if it gets better.” That’s how people lose vision. A small ulcer can turn into a deep scar in 24 to 48 hours. Scarring means permanent blurriness, glare, or even a blind spot. In worst-case scenarios, the infection spreads to the inside of the eye, causing endophthalmitis-a medical emergency that can lead to eye removal.

The FDA and the American Academy of Ophthalmology agree: if you suspect a corneal ulcer, stop wearing lenses immediately and get evaluated within hours-not days. Delaying treatment isn’t just risky. It’s reckless.

Looking Ahead: Are New Lenses Safer?

Yes, modern lenses allow more oxygen than older ones. Some now have antimicrobial coatings. But none are foolproof. The biggest risk isn’t the lens material-it’s how you use it. Studies show that even with advanced lenses, people who sleep in them or skip hygiene still get ulcers at the same high rates.

Technology helps with faster diagnosis, but it doesn’t replace responsibility. The real breakthrough isn’t in the lens-it’s in patient education. Knowing the signs. Knowing the risks. Knowing when to act.

Contacts are convenient. But they’re not toys. They’re medical devices. And like any medical device, misuse has consequences.

Final Thought: Your Vision Isn’t Worth Risking

Contacts are a tool-not a lifestyle. They’re not a second skin. If you’re tempted to sleep in them because you’re tired, or skip cleaning because you’re busy, remember: your eyes don’t have a reset button. One bad night can cost you your sight. The best way to protect your vision isn’t expensive drops or fancy lenses. It’s simple: take them out. Wash your hands. Don’t risk it. Your future self will thank you.