What are the most common red eye causes?

Common causes of red eye include dry eye, allergies, conjunctivitis, eyelid inflammation, corneal irritation, contact lens problems, and broken blood vessels on the eye’s surface. More serious causes can include corneal infection, uveitis, eye injury, or sudden changes in intraocular pressure.

When is red eye an emergency?

Red eye is an emergency when accompanied by severe pain, sudden vision changes, halos around lights, nausea, vomiting, chemical exposure, serious injury, or marked light sensitivity. These symptoms may signal a pressure-related emergency, corneal injury, infection, or inflammation inside the eye.

Can dry eye make my eyes red?

Yes. Dry eye can cause redness, burning, stinging, grittiness, watery eyes, light sensitivity, and fluctuating vision. In Arizona, dry air, wind, air conditioning, screen time, and contact lens wear can worsen dry eye symptoms.

How can I tell if red eye is allergies or pink eye?

Allergies often cause intense itching, watering, and redness in both eyes. Pink eye may cause redness, irritation, discharge, crusting, or swelling. Viral and bacterial conjunctivitis can spread, so an eye exam helps confirm the cause and guide the right next steps.

Should I wear contacts if one eye is red?

No. Remove your contact lenses if your eye is red, painful, irritated, or sensitive to light. Contact lens-related redness can sometimes involve the cornea and may need urgent care, especially if vision changes or pain develops.

Can eye pressure cause a red eye?

Yes. A sudden rise in eye pressure can cause a red, painful eye with blurred vision, halos, headache, nausea, or vomiting. This can be an emergency and needs immediate medical care.

What should I do if my child has a red eye?

A child with mild redness and itching may have allergies or irritation, but redness with pain, light sensitivity, discharge, swelling, injury, or vision changes should be checked promptly. If symptoms are severe or sudden, seek urgent care.

Where can I get red eye evaluated in Arizona?

Barnet Dulaney Perkins Eye Center provides comprehensive eye care at locations across Arizona. If you have red eye with pain, sudden vision changes, injury, or other alarming symptoms, call for guidance during business hours or seek emergency care.

What are the most common red eye causes?

Common causes of red eye include dry eye, allergies, conjunctivitis, eyelid inflammation, corneal irritation, contact lens problems, and broken blood vessels on the eye’s surface. More serious causes can include corneal infection, uveitis, eye injury, or sudden changes in intraocular pressure.

When is red eye an emergency?

Red eye is an emergency when accompanied by severe pain, sudden vision changes, halos around lights, nausea, vomiting, chemical exposure, serious injury, or marked light sensitivity. These symptoms may signal a pressure-related emergency, corneal injury, infection, or inflammation inside the eye.

Can dry eye make my eyes red?

Yes. Dry eye can cause redness, burning, stinging, grittiness, watery eyes, light sensitivity, and fluctuating vision. In Arizona, dry air, wind, air conditioning, screen time, and contact lens wear can worsen dry eye symptoms.

How can I tell if red eye is allergies or pink eye?

Allergies often cause intense itching, watering, and redness in both eyes. Pink eye may cause redness, irritation, discharge, crusting, or swelling. Viral and bacterial conjunctivitis can spread, so an eye exam helps confirm the cause and guide the right next steps.

Should I wear contacts if one eye is red?

No. Remove your contact lenses if your eye is red, painful, irritated, or sensitive to light. Contact lens-related redness can sometimes involve the cornea and may need urgent care, especially if vision changes or pain develops.

Can eye pressure cause a red eye?

Yes. A sudden rise in eye pressure can cause a red, painful eye with blurred vision, halos, headache, nausea, or vomiting. This can be an emergency and needs immediate medical care.

What should I do if my child has a red eye?

A child with mild redness and itching may have allergies or irritation, but redness with pain, light sensitivity, discharge, swelling, injury, or vision changes should be checked promptly. If symptoms are severe or sudden, seek urgent care.

Where can I get red eye evaluated in Arizona?

Barnet Dulaney Perkins Eye Center provides comprehensive eye care at locations across Arizona. If you have red eye with pain, sudden vision changes, injury, or other alarming symptoms, call for guidance during business hours or seek emergency care.

Red Eye Causes: When Redness Is an Emergency in Phoenix

Red eye causes can range from simple dryness or allergies to eye infections, corneal injuries, inflammation, or pressure-related emergencies that need immediate care. At Barnet Dulaney Perkins Eye Center, patients across Phoenix, Mesa, Chandler, Glendale, Goodyear, Surprise, Tucson, Flagstaff, and throughout Arizona can get help understanding what redness may mean and when an eye exam should not wait.

A red eye can look dramatic in the mirror. Sometimes it feels gritty after a long day in Arizona’s dry air. Sometimes it itches during allergy season. Other times, the redness comes with pain, light sensitivity, blurred vision, discharge, or a deep ache, which may indicate something more serious is happening.

The hard part is that many causes of red eye overlap. Dry eye, allergies, conjunctivitis, corneal injury, uveitis, and acute pressure changes can all make the eye look red. The symptoms around the redness often provide the real clues.

When Red Eye Needs Emergency Care

Some redness can wait for a regular eye appointment. Other redness needs urgent evaluation.

Seek immediate medical help if red eye comes with:

Sudden vision loss or a major change in vision
Severe eye pain
New halos around lights
Nausea or vomiting with eye pain
A serious eye injury
Chemical exposure
New light sensitivity
A new curtain, shadow, flashes, or sudden floaters
Redness after sleeping in contact lenses
A painful red eye after surgery or an eye procedure

These symptoms can point to problems involving the cornea, retina, eye pressure, infection, or inflammation inside the eye. If symptoms feel alarming or happen after hours, do not wait. Call 911 or seek emergency care.

What Redness Can Mean: A Quick Comparison

Possible Cause	Common Clues	How Urgent It Can Be
Dry eye	Burning, grittiness, watery eyes, fluctuating vision	Often routine, sooner if painful or worsening
Allergies	Itching, watering, both eyes affected, seasonal pattern	Usually routine unless severe
Conjunctivitis	Pink or red eye, discharge, crusting, irritation	Often prompt, especially if contagious or worsening
Corneal injury	Sharp pain, tearing, foreign body feeling, light sensitivity	Urgent, especially for contact lens wearers
Uveitis	Aching pain, redness, light sensitivity, blurry vision	Urgent
Pressure–related emergency	Severe pain, halos, headache, nausea, blurred vision	Emergency

This comparison can help you think through the pattern, but it cannot replace an exam. A red eye exam lets your eye doctor check your vision, eye pressure, cornea, eyelids, tear film, pupil response, and the inside of the eye.

Dry Eye: Redness With Burning, Grittiness, Or Watery Eyes

Dry eye is one of the most common causes of red eye in Arizona. Dry air, wind, air conditioning, screen time, contact lens wear, and tear film problems can all irritate the eye’s surface.

Dry eye redness often comes with a gritty, sandy, burning, or tired feeling. Some patients also notice watery eyes, which can seem confusing. When the tear film is unstable, the eye may overproduce watery tears that still do not provide lasting comfort.

Dry eye may feel worse after reading, working on a computer, driving, or spending time outdoors. It may also blur vision intermittently. If redness keeps coming back, dry eye treatment may help calm the eye’s surface rather than chasing symptoms with random over-the-counter drops.

Allergies: Red, Itchy, Watery Eyes

Allergies often make both eyes red, itchy, watery, and swollen. The itch is the giveaway. Dry eye may burn. Conjunctivitis may create discharge. Allergy-related redness usually makes patients want to rub their eyes.

Common triggers include pollen, dust, mold, pet dander, smoke, and seasonal changes. In Arizona, windy days can stir up dust and allergens that quickly irritate the eyes.

Try not to rub. Rubbing can make inflammation worse and may irritate the cornea. Cool compresses, preservative-free artificial tears, and allergy eye drops may help some patients, but persistent redness deserves an exam. Not every itchy red eye is “just allergies.”

Conjunctivitis: When Red Eye May Be Pink Eye

Conjunctivitis, often called pink eye, happens when the conjunctiva becomes inflamed. The conjunctiva is the clear tissue that covers the white part of the eye and lines the inside of the eyelids.

Viral conjunctivitis often causes watery discharge and may be accompanied by cold-like symptoms. Bacterial conjunctivitis may cause thicker discharge or crusting, especially after sleep. Allergic conjunctivitis usually causes itching and affects both eyes.

Because viral and bacterial conjunctivitis can spread, good hygiene matters. Avoid sharing towels, wash your hands often, replace contaminated eye makeup, and follow your doctor’s instructions about school, work, contact lenses, and medication.

You should schedule an eye exam if redness, discharge, or irritation worsen, affect vision, cause pain, or do not improve as expected.

Corneal Injury: A Scratch, Foreign Body, Or Contact Lens Problem

The cornea is the clear front surface of the eye. When it gets scratched or irritated, redness can come on fast. A corneal abrasion, embedded debris, a contact lens complication, or chemical exposure may cause sharp pain, tearing, light sensitivity, and a sensation of something stuck in the eye.

Do not try to remove an embedded object. Don’t patch the eye unless a medical professional tells you to. Cease wearing contact lenses if you experience pain or redness.

Contact lens-related redness deserves special caution. A red, painful eye in a contact lens wearer may indicate a corneal infection, which can threaten vision without prompt treatment. Remove the lenses and seek care quickly.

Uveitis: Redness With Light Sensitivity And Aching Pain

Uveitis is inflammation inside the eye. It can cause redness, aching pain, blurred vision, floaters, and sensitivity to light. Unlike mild dryness or allergies, uveitis may feel deeper and more uncomfortable.

Some cases come on suddenly. Others build more slowly. Uveitis may be connected with autoimmune conditions, infections, injury, or other inflammatory problems, although the cause is not always obvious.

This is not a “wait and see for a week” type of red eye. If redness is accompanied by eye pain, light sensitivity, floaters, or blurred vision, schedule an urgent evaluation. Treatment may help control inflammation and lower the risk of complications.

Pressure-Related Emergencies: Severe Pain, Halos, Nausea, Or Blurred Vision

A pressure-related emergency, such as acute angle-closure glaucoma, can cause a painful red eye with blurred vision, halos around lights, headache, nausea, or vomiting. This happens when fluid cannot drain properly, and eye pressure rises quickly.

This type of red eye is an emergency. Waiting can put vision at risk.

Not every glaucoma patient has these symptoms. Many forms of glaucoma develop quietly over time. But sudden redness with severe pain, vision changes, halos, or nausea needs immediate care.

What Your Eye Doctor Checks During A Red Eye Exam

A red eye exam focuses on finding the cause, not just calming the redness. Your eye doctor may check:

Vision changes
Eye pressure
Corneal scratches or infection
Tear film quality
Eyelid inflammation
Pupil response
Light sensitivity
Discharge pattern
Signs of inflammation inside the eye

This is why self-diagnosis can get tricky. A red eye from allergies and a red eye from inflammation may look similar at first glance. The treatment, urgency, and risks can vary widely.

What You Can Do Before Your Appointment

While you are waiting to be seen, a few safe steps may help protect your eyes:

Stop wearing contact lenses if your eye is red, painful, irritated, or light-sensitive. Use preservative-free artificial tears if the eye feels dry or gritty. Avoid eye makeup until symptoms clear. Do not use old prescription drops unless your doctor tells you to. Avoid redness-relief drops that promise to “get the red out” without addressing the cause.

If you have chemical exposure, rinse the eye immediately with clean water or saline and seek emergency care.

Get The Right Care For Red Eye In Arizona

The causes of red eye are not always obvious, and the safest next step depends on the full symptom pattern. Mild redness due to dryness or allergies may require supportive care and a routine exam. Redness with pain, light sensitivity, vision changes, injury, or nausea needs urgent attention.

Barnet Dulaney Perkins Eye Center provides comprehensive eye care at locations across Arizona, including the Phoenix metro area, Northern Arizona, and Tucson-area communities. If you are unsure what type of appointment you need, the team can help direct you based on your symptoms, vision needs, and eye health history.

If your red eye is painful, sudden, or affecting your vision, do not wait. Schedule an eye exam with Barnet Dulaney Perkins Eye Center or seek emergency care for severe symptoms.

Red Eye Causes: Common Reasons And When Redness Is An Emergency