A red eye is one of the most common reasons people visit an eye doctor. It looks alarming, but many causes are minor and clear up on their own. The color comes from blood vessels on the surface of your eye widening or breaking. The key is figuring out whether you are dealing with a burst vessel, an infection, or something more serious. This guide covers the main causes and what you can do about them.
What Causes A Red Eye?
A red eye happens when the tiny blood vessels on the white part of your eye (the sclera) expand or rupture. This can happen for many reasons. The most common include lack of sleep, dry air, allergies, and staring at a screen for too long.
Infections, injuries, and foreign objects can also cause redness. So can more serious conditions like acute glaucoma or inflammation inside the eye. The cause matters far more than the redness itself. Knowing what to look for helps you decide whether to wait it out or seek care quickly.
Why Is My Eye Turning Red: The Most Common Reasons
Most red eyes fall into a few familiar categories. Here is what you are likely dealing with if you have no other symptoms.
Subconjunctival hemorrhage. This is a broken blood vessel on the surface of the eye. It looks like a bright red patch on the white part. It can happen from coughing, sneezing, heavy lifting, or rubbing your eye. It looks dramatic but is usually harmless. The blood absorbs on its own over one to two weeks.
Dry eye. When your eyes do not produce enough tears or the tears evaporate too quickly, the surface becomes irritated. The eyes look red and feel gritty or burning. Dry eye is more common with age, in dry climates, and with prolonged screen use.
Allergies. Pollen, pet dander, dust mites, and mold can trigger an allergic reaction in the eyes. Both eyes usually turn red and itchy. They may water excessively. This is often seasonal or tied to a specific environment.
Conjunctivitis (pink eye). This is inflammation of the clear membrane covering the white of the eye and the inside of the eyelids. Viral conjunctivitis often comes with a cold and watery discharge. Bacterial conjunctivitis usually produces thicker, yellow or green discharge. Both make the eye red and irritated.
Contact lens irritation. Wearing contacts too long, sleeping in them, or using them past their replacement date can cause redness. This happens because the lens reduces oxygen flow to the cornea. The eye becomes irritated and can develop serious infections if not addressed.
When A Red Eye Is An Emergency
Some red eyes are urgent. If you have any of the following symptoms, see an eye doctor or go to urgent care the same day.
- Sudden vision loss or blurred vision
- Severe eye pain, not just discomfort
- Sensitivity to light (photophobia)
- Nausea or vomiting with the red eye
- A visible injury or chemical exposure
- A red eye with a history of eye surgery
Acute angle-closure glaucoma is a medical emergency. The pressure inside the eye rises rapidly. Symptoms include severe pain, headache, nausea, vomiting, and blurred vision. The pupil may look mid-dilated and not react to light. This requires immediate treatment to prevent permanent vision loss.
Keratitis is an infection of the cornea, the clear front surface of the eye. It causes redness, pain, tearing, and sensitivity to light. It is more common in contact lens wearers. If left untreated, it can scar the cornea and reduce vision.
Uveitis is inflammation inside the eye. It causes redness, pain, and light sensitivity. It is often associated with autoimmune conditions. It requires medical treatment to prevent complications like glaucoma or cataracts.
What To Do For A Red Eye At Home
For mild redness without pain or vision changes, home care is reasonable. Start by removing contact lenses if you wear them. Do not put them back in until the eye is completely white and comfortable.
Use artificial tears. Lubricating eye drops can soothe dryness and flush out irritants. Choose preservative-free drops if you use them more than four times a day. Avoid drops that claim to “get the red out.” These contain vasoconstrictors that shrink blood vessels temporarily. They do not treat the cause and can cause rebound redness when they wear off.
Apply a clean, cool compress over closed eyes for five to ten minutes. This can relieve irritation from allergies or mild strain. For bacterial conjunctivitis, a warm compress may feel more soothing. Wash your hands before and after touching your eyes.
Rest your eyes. If you have been staring at screens, take breaks using the 20-20-20 rule. Every 20 minutes, look at something 20 feet away for 20 seconds. This gives the eye muscles a break and encourages blinking.
Over-the-counter antihistamine eye drops can help if allergies are the cause. Look for drops containing ketotifen, which is available without a prescription. They reduce itching and redness caused by allergic reactions. They do not help with infections or dry eye.
What Not To Do
Do not rub your eye. Rubbing can worsen irritation and can turn a minor issue into a scratched cornea. If you have a foreign object in your eye, rubbing can push it deeper into the tissue.
Do not use redness-relief drops as a long-term solution. Products containing tetrahydrozoline or naphazoline shrink blood vessels. Overuse leads to rebound redness. The eye becomes dependent on the drops and looks worse when they wear off.
Do not share eye makeup, towels, or pillowcases if you suspect an infection. Viral and bacterial conjunctivitis are highly contagious. Wash your hands frequently and avoid touching your face.
Do not use someone else’s prescription eye drops. Antibiotic drops for one person’s infection may be wrong for yours. Using steroid drops without a doctor’s supervision can worsen certain infections and raise eye pressure.
When To See A Doctor
See an eye doctor if the redness lasts more than a few days despite home care. Also see a doctor if you have discharge that is thick or colored, if the redness gets worse, or if you have any eye pain. Contact lens wearers should see a doctor at the first sign of redness or discomfort. The risk of corneal infection is higher in this group.
If you have recurrent red eyes, get an evaluation. Chronic redness can be a sign of an underlying condition like rosacea, blepharitis, or severe dry eye. These conditions can be managed but usually need a proper diagnosis first.
Can You Prevent A Red Eye?
Not all red eyes are preventable, but many are. Keep your eyes lubricated in dry environments. Use a humidifier in winter and avoid direct airflow from fans or vents. Stay hydrated and blink fully and often when using screens.
Follow contact lens hygiene strictly. Wash your hands before handling lenses. Clean and store them as directed. Replace them on schedule. Never sleep in lenses unless your eye doctor has specifically approved it for your eyes.
Protect your eyes from injury. Wear safety glasses when working with tools, chemicals, or yard equipment. Wear sunglasses outdoors to reduce UV exposure and protect against wind and dust.
Manage allergies proactively. If you know pollen triggers your symptoms, start antihistamine treatment before the season begins. Wash your face and hands after being outdoors and keep windows closed on high-pollen days.
Frequently Asked Questions
Can a red eye be a sign of something serious?
Yes, but it is not common. Severe pain, vision loss, nausea, or light sensitivity with a red eye can signal glaucoma, infection, or inflammation inside the eye. Seek medical care the same day if you have these symptoms.
How long does a broken blood vessel in the eye take to heal?
A subconjunctival hemorrhage usually clears in one to two weeks. The blood slowly absorbs and the eye returns to normal. It may change color from red to yellow as it heals.
Should I use eye drops for a red eye?
Artificial tears are safe for mild redness from dryness or irritation. Do not use redness-relief drops regularly. If you suspect an infection or have pain, see a doctor before using any medicated drops.
Can I wear contact lenses with a red eye?
No. Remove your contacts immediately and wear glasses until the eye is completely white and comfortable. Wearing contacts with a red eye raises the risk of corneal infection and can make the problem worse.
