A corneal ulcer is a sore on the clear front of the eye. It is painful, can scar, and needs prompt care to protect vision. Most ulcers come from infection, often after a small scratch or a contact lens problem.

Symptoms

Symptoms include a painful red eye, light sensitivity with tearing, and blurred vision or a white/grey spot on the cornea. Treat this as urgent, especially if it follows contact lens wear or an eye injury.

Causes

Bacteria are the most common cause, but viruses, fungi, and Acanthamoeba can also infect the cornea. Risk rises with poor lens habits such as sleeping in lenses, letting them touch water, or wearing damaged lenses. This can happen with daily contact lenses or silicone hydrogel contacts if they’re handled the wrong way.

Who Is at Higher Risk?

People who extend wear time, sleep or nap in lenses, swim or shower in lenses, have very dry eyes or lid inflammation, or have had recent eye trauma or surgery. Rubbing the eyes a lot or using old solution also adds risk.

Diagnosis

An eye doctor examines the cornea with a microscope and may use a dye to outline the sore. Larger or central ulcers are often cultured to match treatment to the germ. Starting treatment quickly helps protect sight while results are pending.

Treatment and Recovery

Most bacterial ulcers need frequent antibiotic drops at first, then fewer as the eye improves. Viral or fungal ulcers need targeted antivirals or antifungals. Some cases add an anti-inflammatory drop later under close supervision. Healing time depends on size and cause; severe ulcers can scar and, in rare cases, need a corneal transplant.

Prevention Tips for Contact Lens Users

• Don’t sleep in lenses unless your eye-care professional has approved it.
• Keep lenses and cases away from water.
• Replace lenses and cases on schedule and use fresh solution each time.
• If case care is hard to keep up with, consider daily contact lenses for a fresh pair each day.
• If you use month-long contacts, stick to the recommended schedule and avoid stretching wear time.
• Wearers of toric contact lenses for astigmatism should follow the same hygiene steps and timely replacement.
• Remember that silicone hydrogel contacts let more oxygen through but still carry infection risk with poor habits.
• If eyes feel sore or irritated, remove lenses and get advice before wearing them again.

Getting Back to Normal After an Ulcer

Your clinician will advise when it’s safe to return to contacts and what changes to make. That plan might include a new fit, moving to a daily schedule, limiting wear time, or switching lens types. Good hygiene and avoiding overnight wear lower the chance of another ulcer.

Quick Takeaway

A painful, light-sensitive red eye, especially in a contact lens wearer, needs same-day assessment. Early treatment protects sight and supports recovery.