The cornea is the transparent, dome-shaped "window" that covers the front of the eye. A nick, scratch or scrape of the cornea is called a corneal abrasion.
Corneal abrasions are one of the most common forms of eye injury. In some cases, they are caused by the direct impact of a sharp object, such as a pencil, staple, nail or sewing pin. They also can be caused by small, airborne particles, such as dust, sand or flying debris from soldering, woodworking or weed trimming. Even fingernails can cause a corneal abrasion.
Although corneal abrasions can occur in people of all ages, people more likely to have this happen include:
- Infants who scratch their eyes unintentionally with untrimmed fingernails
- School children who play with pencils, pens and other pointed objects
- Athletes who play sports without using some form of eyewear to protect against dust, sand or an accidental scratch from another player's finger. More eye injuries occur in baseball and football than in other sports.
- People who have hobbies or crafts that use pointed tools, such as sewing and wood carving, or that produce dust, such as woodworking and gardening
- Workers who are exposed to eye hazards on the job, especially those involved in farming or construction
- Anyone who inserts contact lenses without properly cleaning their hands and their lenses beforehand
The cornea has several layers of cells and membranes. The thin top layer, called the epithelium, is composed of sensitive cells that are similar to skin. Below this surface layer lies a tough, protective structure called Bowman's membrane. The epithelium and Bowman's membrane together make up only 10% of the thickness of the cornea. They are the two layers most involved in corneal abrasions. Abrasions that involve only the surface epithelium have a good chance of healing without any long-term effects. However, deeper abrasions that penetrate through the Bowman's membrane are more likely to cause permanent corneal scars. These scars are opaque, whitish areas in the cornea that may interfere with normal vision.
In the United States, corneal abrasions are the most common eye injury in children. Boys get corneal abrasions twice as often as girls between the ages of 5 and 15. Most corneal abrasions are superficial injuries that involve only the surface layer of the cornea. Although these abrasions can be very painful, they don't usually cause permanent vision problems.
Symptoms of a corneal abrasion can include:
- A feeling that you have something in your eye
- A teary, red eye
- Blurred vision in one eye, headache, or unusual sensitivity to light
Your doctor will examine your eye with a light to check for any obvious corneal injuries, small specks of dust or dirt, or other foreign objects. To confirm the diagnosis of a very small corneal abrasion, your doctor may need to place a small drop of a yellow-orange dye called fluorescein into your eye. This dye will cause any area of abrasion to look greenish under a special blue light.
Usually, if you have only a mild corneal abrasion, you will not need any other tests. However, if your injury is more serious, your doctor may examine your eye with device called a slit lamp, and also test your vision.
With proper treatment, symptoms of a mild corneal abrasion almost always improve or disappear totally within 24 to 48 hours. For more severe abrasions, symptoms often last longer.
Most corneal abrasions can be prevented, especially those that happen in the workplace or during sports. To help prevent corneal abrasions and other types of eye trauma, you can take these actions:
- Carefully trim your infant's fingernails.
- Use appropriate protective eyewear at work. Studies have shown that goggles and other protective eyewear can reduce the risk of work-related eye injuries by more than 90%. For more information, contact the U.S. Department of Labor's Occupational Safety and Health Administration.
- If you are an athlete, ask an experienced ophthalmologist, optometrist or optician for help in selecting protective eyewear that is appropriate for your sport. For example, sports goggles with polycarbonate lenses may be recommended for athletes who play handball, soccer, badminton or basketball.
- Have your protective eyewear fitted by a professional. A proper fit will help to prevent dust and flying debris from going around or under your eyewear.
- Clean your contact lenses thoroughly before you insert them, as directed by your eye care professional. Also, make sure that your hands are clean whenever you handle your lenses.
If you think that you have dust or dirt in your eye, avoid the urge to rub it. If you are wearing contact lenses, remove them immediately. Next, try washing your eye for several minutes with clear, clean water to see if this relieves the problem. If no water is available, pull your upper eyelid outward and downward over your lower eyelid. This simple maneuver may allow your natural flow of tears to flush the debris away. If these strategies do not relieve your symptoms, or if you suspect that your eye has been scratched by a sharp object, even a fingernail, call your doctor.
If you have a corneal abrasion, your doctor will prescribe an antibiotic in either eye drops or an eye ointment to prevent an infection from developing in the injured area. You doctor also may recommend that you take acetaminophen (Tylenol), ibuprofen (Advil, Motrin and other brand names), or another nonprescription pain reliever to treat your eye pain.
If your eye is overly sensitive to light, or if your eye pain is not relieved by nonprescription medications, your doctor may prescribe drugs called cycloplegic drugs. These medications will relieve your eye symptoms by temporarily reducing the activity of muscles that control the size of your pupil.
If you usually wear contact lenses, do not wear them again until your doctor says that you can. Also, avoid wearing eye makeup until your corneal abrasion has healed completely.
Once you have completed one day of treatment for a corneal abrasion, your doctor will want an update on your symptoms to confirm that your eye has started to improve. This usually means either a follow-up office visit for an eye check, or some other form of contact with your doctor.
Call your doctor immediately if you have symptoms of a corneal abrasion, or if you are being treated for a corneal abrasion and your symptoms do not improve within 24 hours after treatment begins.
With proper treatment, most superficial corneal abrasions heal quickly without any complications. In general, the milder the abrasion, the faster the recovery time. Deeper abrasions that penetrate through Bowman's membrane are more likely to cause permanent corneal scars that can interfere with vision. If necessary, severe scarring often can be treated successfully with a corneal transplant.
National Eye Institute
2020 Vision Place
Bethesda, MD 20892-3655
U.S. Department of Labor's Occupational Safety & Health Administration (OSHA)
200 Constitution Ave.
Washington, D.C. 20210
Prevent Blindness America
211 West Wacker Drive
Chicago, IL 60606