Common Reasons You Have Red Eyes

Posted on July 24, 2025 in Vision Health

Have you ever caught a glimpse of yourself and noticed your eyes are looking a bit red? Red eyes are a common symptom for many different conditions, which can vary in severity. Almost everyone will have red eyes at some point. Understanding the causes of red eyes and knowing how to get treatment is crucial.

Common and manageable causes of red eyes 

Red eyes are common, and in many cases they aren't a big concern. In fact, sometimes they will go away without extra help. Common reasons for red eyes include:

Allergies

If your eyes suddenly become itchy, watery, and red, you may be having an allergic reaction to a substance. Allergies occur when your immune system reacts to foreign proteins. 

• Causes: Exposure to pollen, pets, mold, and dust.
• Treatment: Over-the-counter oral antihistamines, doctor-prescribed antihistamines, or decongestant eye drops.

Conjunctivitis

Pink eye is the viral form of conjunctivitis, a common and contagious infection. Symptoms can vary, but you can typically spot it by the discharge from the eyes and their pinkish or red color (clear discharge is viral, discharge with a yellowish tint is typically bacterial).

• Causes: Viral or bacterial infections.
• Treatment: Remove makeup and contacts immediately. If the condition doesn't go away on its own, a doctor may prescribe antibiotic eye drops or ointments depending on the cause.

Note: Conjunctivitis caused by a virus cannot be treated with antibiotics. Be sure to speak with a doctor for additional information and treatment options.

Dry eye

If your eyes aren't producing enough tears or you are not blinking properly, you may experience dry eyes. This condition is often associated with a scratchy or burning sensation, sensitivity to light, blurred vision, and red eyes.

• Causes: Age, illness, blinking less often, dry environments, medications, and contacts. 
• Treatment: Lubricating eye drops, staying hydrated, avoiding triggers, giving your eyes a break (especially while using a screen), and others.

Broken blood vessels 

If you look in the mirror and see a startlingly red eye, it's possible you've accidentally broken a blood vessel. This condition, also known as a subconjunctival hemorrhage, occurs when tiny blood vessels burst and bleed onto the eye.

• Causes: Eye rubbing, intense coughing or sneezing, a direct injury to the eye, blood thinning medications, and more.
• Treatment: Broken blood vessels look more alarming than they are. They often go away on their own. If you have recurrent subconjunctival hemorrhages or pain, be sure to speak to your doctor.

Serious and urgent causes of red eyes

In certain situations, the reasons behind red eyes are serious and need medical intervention. These include:

Acute angle-closure glaucoma

This condition occurs when the eye's fluid pathways are blocked. This prevents proper drainage and increases pressure in the eye. Red eyes, severe headache, nausea or vomiting, and eye pain are all signs of this medical emergency.

• Causes: Acute angle-closure glaucoma can be caused by the thickening of the natural lens and aging. However, it may also be triggered by dilating eye drops and certain medications.
• Treatment: Seek medical attention immediately. A doctor may prescribe eye drops or oral medication. In severe cases, your doctor may perform an iridotomy operation, which helps relieve pressure in the eye by placing a tiny hole in the iris.

Uveitis

Uveitis occurs when the middle layer of the eye becomes inflamed, causing the eye to appear red.

• Causes: Autoimmune disorders, infection, or cancer.
• Treatment: Steroids and anti-inflammatory medications in the form of pills, eye drops, injections, or implants.

Corneal ulcer

A corneal ulcer is a type of eye injury identifiable by an open sore on the cornea, a symptom of which can be red eyes.

• Causes: Trauma, infection from bacteria, viruses, fungi, or improper contact lens use, or autoimmune diseases.
• Treatment: Seek medical attention immediately. A doctor may prescribe antibiotic or antifungal treatment to help prevent vision loss or corticosteroids.

Understanding the causes of red eyes can protect your eye health 

Recognizing the underlying causes of red eyes is crucial for maintaining eye health. Awareness can prevent complications, ensuring that minor issues don't escalate into serious problems. If you are experiencing pain, you should seek a medical opinion. 

Looking for ways to protect your eye health? Check out “The Link Between Eye Health and Lifestyle Choices”.