There are lots of reasons an eye can be red.
Some common ones include:
- foreign body
Getting hit in the eye or getting dirt or soap in the eye are usually pretty obvious and require evaluation and treatments that we’ll put aside for now.
Infection and inflammation can be picked apart, but sometimes it’s complicated and they overlap: what starts out as allergy and inflammation can be touched and rubbed. This can lead to infection.
First, some basics. The red eye, commonly called “pink eye” is more correctly called conjunctivitis. The conjunctiva is the layer that wraps the eye–think of plastic wrap–and whenever you see –itis after a body part that means inflammation. So conjunctivitis is inflammation of the conjunctiva.
What inflames the conjunctiva? Usually allergy or infection.
With allergy (allergic conjunctivitis), the eye is swollen, itchy and red. There can also be a watery discharge. This is treated with cool compresses and antihistamines (loratadine, cetirizine, fexophenadine, diphenhydramine) taken by mouth as well as applied as separate antihistamine eye drops.
With infection, the eye is swollen and there’s usually a discharge.
Eye infections can be caused by viruses or bacteria. They can be spread by getting coughed or sneezed on and by touching something infected with viruses or bacteria–think towels, surfaces, your hands–and then touching the eye.
Call the doctor for the red eye because it’s often difficult to differentiate viral conjunctivitis from bacterial conjunctivitis. Both require specific treatments. Bacterial conjunctivitis, because it’s caused by bacteria, is treated with antibiotic eye drops your doctor will prescribe. Very young children with infectious conjunctivitis will also often have an ear infection.
Infectious conjunctivitis is highly contagious. Children are usually excluded from daycare or school for 24 hours while treatment (usually eye drops) are begun. Wash and change the sheets and towels to keep it from spreading in the hospital and keep surfaces clean.
One good way to avoid conjunctivitis–and infections in general–is to never touch your eyes, nose or mouth unless you’ve just washed your hands. This is impossible for young children, but worth teaching your school age child and practicing yourself.