What Causes a Scratched Cornea?

The cornea is the clear layer that protects the front of the eye from foreign bodies and germs and helps filter out ultraviolet light. It serves a vital role in vision, helping the eye to focus on both near and distant objects. The cornea completely covers the colored region of the eye — the iris — and the pupil. A scratched cornea or corneal abrasion occurs when the cornea becomes damaged due to a trauma to the eye.

Common Causes

An accidental poke to the eye with a fingernail or other object is usually the cause of a scratched cornea. Foreign objects entering the eye, such as sand or sawdust, can also leave abrasions, as can rubbing the eye too hard or splashing chemicals. Some eye infections can also damage the cornea.

Scratched Corneas and Contact Lenses

Contact lens use increases the likelihood of scratching the cornea, specifically when an individual fails to follow their optician’s guidelines for safe contact lens use. Poor fit and improper cleaning that allows dirt or dust to gather on the surface of the lens can scratch the cornea. So, too, can regularly wearing contact lenses for longer than the recommended time.

Symptoms

A scratched cornea often causes pain and discomfort, especially when blinking. The person is likely to experience a gritty sensation, as though there is dust or sand in the eye. This can cause the eye to produce more tears than normal to try to flush out the irritant. The eye may also appear red and inflamed. A scratched cornea can cause blurry vision and may make the individual more sensitive to light.

When to Seek Help

The first sign of a scratched cornea is often a sensation that something is stuck in the eye. It is important not to rub the eye or attempt to remove any foreign body. Instead, blinking or gently rinsing the eye with a sterile saline solution can help to remove any small particles causing the irritation. If the person still feels there is something in their eye or has accompanying pain, redness, or light sensitivity, they should see a doctor as soon as possible, as they may require treatment for a corneal abrasion.

Diagnosis

To diagnose a scratched cornea, the doctor will examine the eye thoroughly for any foreign bodies or visible signs of a scratch. She will ask the person to describe their symptoms and what, if any, obvious injury to the eye has caused the discomfort. To get a clearer view of the cornea, the doctor may use a special dye called an eye stain. This will help to make the scratch more visible and also highlight any foreign bodies remaining in the eye.

Treating a Scratched Cornea

To treat a scratched cornea, the doctor will carefully remove any foreign body remaining in the eye. Minor scratches should heal on their own in a few days. However, the doctor may prescribe eyedrops or ointment to prevent infection and reduce pain. If the patient is sensitive to light, the doctor may recommend an eye patch or sunglasses

Self-Care

Following treatment for a scratched cornea, the individual should take care not to rub their eye and avoid contact lenses until the scratch has completely healed. Symptoms that do not improve, or increased redness, pain, or blurry vision can be signs of an infection or other complication requiring further treatment.

Prevention

It is possible to prevent some corneal abrasions with proper eye care. People who wear contact lenses should keep them clean and remove and replace them as instructed. Anyone working with chemicals or other irritants should wear proper eye protection to stop foreign particles or hazardous substances from entering the eye. Infections should be treated promptly, and irritants should be carefully removed using proper methods, not by rubbing the eyes.

Long-Term Damage

In some cases, a scratched cornea can lead to long-term damage. This is more likely to occur if the person fails to seek treatment. Untreated or very severe corneal abrasions can lead to infections, corneal ulcers, and scarring. Over time, this can cause permanent loss of vision.

Risk Factors

People who have had a previous corneal abrasion are at a higher risk of the condition recurring. Playing certain sports can also increase risk if trauma to the face is likely. Certain occupations, including those requiring work with chemicals or in an environment where there are likely to be stray particles that could enter the eye, can also raise one’s risk, especially if individuals fail to wear proper eye protection.