Contact Lens Infections: Corneal Ulcers vs. Corneal Infiltrates

Contact lenses are a great option for clear, glasses-free vision, but they also require proper care. When contacts are worn too long, slept in, exposed to water, or not cleaned correctly, the cornea can become irritated, inflamed, or infected. The cornea is the clear front surface of the eye, and contact lens-related problems can become serious quickly.

Two common terms patients may hear are corneal ulcer and corneal infiltrate. They can sound similar, and both may cause redness or discomfort, but they are not the same thing.

What Is a Corneal Infiltrate?

A corneal infiltrate is an area of inflammation in the cornea. It happens when inflammatory cells collect in the corneal tissue. In contact lens wearers, infiltrates can develop from lens irritation, overwear, poor lens fit, deposits on the lens, bacteria on the lens surface, or an immune reaction.

Some corneal infiltrates are sterile, meaning they are inflammatory but not actively infected. These may cause mild to moderate redness, irritation, tearing, light sensitivity, or a foreign-body sensation. However, even a sterile infiltrate needs to be evaluated because it can look similar to an early infection. Contact lens-associated infiltrative keratitis can cause redness, watering, light sensitivity, and discomfort, and it is important to distinguish it from sight-threatening microbial keratitis.

What Is a Corneal Ulcer?

A corneal ulcer is more serious. It usually means there is an open sore or defect on the cornea, often associated with infection. In contact lens wearers, this is commonly referred to as microbial keratitis or infectious keratitis.

Bacterial keratitis can cause sudden eye pain, significant redness, light sensitivity, discharge, decreased vision, and excessive tearing. It can progress quickly and may threaten vision if not treated promptly.

Contact lenses are medical devices, and improper wear, cleaning, or storage can increase the risk of microbial keratitis.

Corneal Ulcer vs. Corneal Infiltrate: What’s the Difference?

A corneal infiltrate is usually an inflammatory spot in the cornea. It may or may not be infected.

A corneal ulcer usually involves a break in the corneal surface, often with infection, and is treated more urgently.

In simple terms:

Feature	Corneal Infiltrate	Corneal Ulcer
Main issue	Inflammation in the cornea	Open sore, often infected
Infection present?	Sometimes, but not always	Often yes
Pain level	Mild to moderate, but can vary	Often more painful
Vision changes	May be mild or absent	More likely to affect vision
Urgency	Needs prompt exam	Needs urgent/same-day care
Contact lens wear	Stop lenses immediately	Stop lenses immediately

The challenge is that patients cannot reliably tell the difference at home. A small infiltrate can look harmless but still need treatment, and an early ulcer may not feel severe at first.

Warning Signs Contact Lens Wearers Should Not Ignore

Remove your contact lenses and seek eye care promptly if you notice:

• Eye pain

• Increasing redness

• Light sensitivity

• Blurry or reduced vision

• Discharge

• A white or gray spot on the cornea

• Tearing that does not improve

• Symptoms that continue after removing your lenses

If you have pain, light sensitivity, discharge, or decreased vision, you should be seen the same day. Contact lens-related keratitis is one of the most common infections associated with contact lens wear.

Why Sleeping in Contacts Is Risky

Sleeping in contact lenses increases the risk of corneal problems because the lens reduces oxygen to the cornea and can trap bacteria against the eye. Even if your lenses are labeled for extended wear, they should only be worn overnight if your eye doctor has specifically approved it.

The CDC recommends avoiding sleeping in contact lenses unless directed by an eye care provider.

Water and Contact Lenses Do Not Mix

One of the most important rules of contact lens safety is to keep contacts away from water. That means no showering, swimming, hot tubs, or rinsing lenses with tap water while wearing contacts.

Water exposure can increase the risk of serious infections, including rare but severe infections such as Acanthamoeba keratitis. The CDC recommends keeping contact lenses away from all water.

What Your Eye Doctor Looks For

During an urgent contact lens exam, your optometrist may check:

• Visual acuity

• Corneal staining with fluorescein dye

• Size, depth, and location of the infiltrate or ulcer

• Whether there is an epithelial defect

• Discharge or anterior chamber inflammation

• Contact lens fit and lens hygiene habits

• Whether cultures or referral are needed

Treatment depends on whether the condition appears sterile, infectious, mild, central, peripheral, or vision-threatening. Some cases may require antibiotic eye drops, temporary discontinuation of contact lens wear, close follow-up, or referral to a corneal specialist.

How to Lower Your Risk of Contact Lens Infections

Healthy contact lens habits make a big difference:

• Wash and dry your hands before handling lenses.

• Do not sleep in contacts unless approved by your doctor.

• Never rinse or store lenses in water.

• Avoid swimming or showering in contacts.

• Use fresh contact lens solution every time.

• Replace your lens case regularly.

• Do not “top off” old solution.

• Replace lenses on schedule.

• Do not wear contacts when your eyes are red or painful.

• Keep up with your contact lens exams.

The CDC emphasizes that contact lenses are medical devices and proper wear, cleaning, and storage are essential for reducing infection risk.

When to Call OPTISM

If you wear contact lenses and develop a red, painful, light-sensitive, or blurry eye, do not wait it out. Remove your lenses and schedule an eye exam as soon as possible.

At OPTISM in Tampa, we evaluate contact lens-related eye problems, corneal irritation, corneal infiltrates, and suspected corneal ulcers. Early treatment can help protect your vision and prevent complications.

Concerned about a contact lens infection? Contact OPTISM for prompt eye care in Tampa.