Why Are My Eyes Red?


Dr. Rica McRoy, and Dr. Alana Coker, R City Eye Care

By Dr. Alana Coker
R City Eye Care

Many different causes can contribute to red eyes, but the most common is Dry Eye Disease (DED). When DED is the cause of redness, the eyes may be constantly red or become increasingly red throughout the day. Typically, patients with DED will also feel that their eyes are dry or may have burning, irritation, or even excessive watering.


Although this seems counterintuitive, the body is trying to fix the dryness by over-producing water. The redness is usually mild to moderate when DED is the culprit.

Living in Huntsville, we all know allergies can contribute to red eyes. In most cases, allergic conjunctivitis affects both eyes simultaneously and causes itching and watering. It can also cause a thick, stringy discharge. In extreme cases, fluid can become trapped behind the conjunctiva and cause a bubble-like appearance on the eyes’ surface, a condition called chemosis. Additionally, the eyelids can become swollen and red in extreme cases.

Infectious conjunctivitis usually falls into one of two categories: bacterial or viral. Bacterial conjunctivitis is more common in children and typically effects just one eye, although it can be transferred to the other eye in cases of cross-contamination. It produces a thick, yellow-green discharge, and the eye is often crusted shut upon waking. Viral conjunctivitis is more common in adults and often accompanies a “cold” or upper respiratory infection. It is usually in both eyes, although one may be affected first, and often produces a white or yellow discharge that is normally thinner than the discharge produced by bacteria.

Infections related to contact lenses are also a common cause of red eye(s), especially when contact lenses are overworn or not cared for properly. The most serious is a corneal ulcer, which is usually caused by bacteria. Corneal ulcers cause redness, pain, tearing, light sensitivity, and blurred vision. These infections need to be treated aggressively to prevent long-term complications or vision loss. Another cause of red eye(s) in contact lens wearers is infiltrative keratitis, which is a form of inflammation. The response is typically milder than a corneal ulcer, and the eye(s) become red, irritated, and inflamed due to bacteria on contact lens surface.

A subconjunctival hemorrhage causes extreme redness that is typically localized to one part of the eye. It occurs when one of the small blood vessels on the surface of the eye bursts and spills blood into the space behind the conjunctiva. It is usually harmless and can be caused by coughing, sneezing, vomiting, or trauma. It is more common in people who take aspirin or prescription blood thinners. Rarely, it can be a sign of something more serious, like high blood pressure or a blood clotting disorder, usually in recurrent cases. Subconjunctival hemorrhages can take several weeks to fully clear, but, although unsightly, they are not an infection risk.

If you have a red eye or eyes, the best course of action is to see your optometrist to determine the cause and appropriate treatment. Let’s see better together!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s