Why is My Eye Red?

Sometimes it is difficult to know why your eyes become red and irritated as red eyes are caused by a number of different things, such as allergies, infections, and contact lenses.

If you are experiencing red eyes there are a number of different methods you can use to treat them which we will detail in this article.

We will also cover when you need to see your doctor about your eyes and how to prevent red eyes from happening in the first place.

What are red eyes?

Red eyes, also called bloodshot eyes, are a broad term for when the small vessels in your eye become irritated causing them to expand and become dilated which increases blood flow.

The whites of your eyes may also look red or pink, and you may have tiny broken blood vessels in your conjunctiva, which is the clear membrane that covers the white part of your eye.

You may also have itchiness, burning, changes in vision, excessive tears, or a feeling that something is in your eye, and your eyes can also become swollen.

It is also possible for only one eye to be red and irritated while the other is perfectly normal and it can come on suddenly or take time to develop depending on the cause of it.

Many causes of red eyes are easily treatable, short-lived, and do not cause any permanent harm. However, there are some serious conditions that cause red eyes that you need to be aware of if you have them.

What causes red eyes?

A number of different things can cause your eyes to become red and irritated, and it can also be a combination of several factors.

Some common causes of red eyes are:


If you have seasonal allergies or allergies to pet dander, dust mites, or pollen you may experience itchy, watery, bloodshot eyes.

Allergies cause the release of histamines in your body which can lead to swelling and inflammation in your eyes and sinuses, sneezing, and a runny nose.

You may also have itchiness in other areas of your body such as your nose, throat, or skin.

Dry eye

If you do not have enough tears or the quality of your tears is poor due to a lack of lipids that help retain moisture, it can cause dry eye and may include the following common symptoms:

  • A gritty feeling or a scratchy feeling on your eye
  • Itchy
  • Irritated heavy eyelids
  • An inability to make tears
  • An excess of tears
  • Burning sensation
  • Pain
  • Blurry vision

Dry eye is more common if you are an older adult, if you are pregnant or taking birth control pills, if you spend a lot of time on the computer, if you live in a dry or windy climate, and if you smoke.


Blepharitis is an inflammatory condition where you have an inflamed eyelid that is also red and itchy.

It is caused by a buildup of bacteria at the base of your eyelashes or an overgrowth of the yeast that naturally lives on your skin.

If you suffer from dandruff, seborrheic dermatitis, or dry skin, you are more likely to have blepharitis.

Conjunctivitis (pink eye)

Conjunctivitis or pink eye is an inflammation of your conjunctiva, which is the clear membrane that covers the white part of your eye and the inner surface of your eyelids.

It can be caused by a virus or bacteria, can be very contagious, and is common among children. The symptoms of conjunctivitis are:

  • Red eyes
  • Itchy eyes
  • Eye fatigue
  • Watery eyes
  • Swelling of your eyelids
  • A burning sensation
  • Crusting of your eyelashes when you wake up in the morning
  • A yellow, green, or white discharge from your eye
  • Photosensitivity which is sensitivity to light

If you have pink eye you need to see your doctor and also wash your hands frequently while trying not to touch your eyes or face.

Viral eye infections of pink eye will usually go away on their own but if you have bacterial conjunctivitis, you will likely need antibiotics to treat it which come in the form of prescription eye drops.

Top tips for Seasonal Allergic Conjunctivitis – Red, itchy eyes?


An eye inflammation of the episclera, which is the thin, transparent layer that covers the white part of your eye is called episcleritis.

It usually affects only one eye and is benign and not serious. Episcleritis often goes away on its own within a week or two.


Glaucoma is a condition that damages your optic nerve and can lead to vision loss or blindness. It is caused by an increase in pressure inside of your eye, but it does not always cause symptoms.

If you have glaucoma you may experience the following:

  • Severe headaches
  • Eye pain
  • Nausea
  • Vision changes such as blurry vision or seeing rainbows or halos around light in your vision

Injury to your eye

When you have an eye injury, your eye may become red due to irritation or your blood vessels dilating to allow increased blood flow to the injured area.

Examples of eye injuries include a scrape on your eyeball also called a corneal abrasion or chemical exposure to your eyes from cleaning solutions and other irritants.

If you experience this type of eye injury it is an emergency situation and you need to seek medical attention.

You also can rupture the blood vessels in your eye which is called a subconjunctival hemorrhage that leaves what looks like blood spots on your eye.

A broken blood vessel can be caused by something as innocuous as a strong sneeze, vomiting, or lifting something heavy.

These minor injuries usually have no pain and there is no need to see your doctor unless it is irritating your eye in some way.

Particles or foreign objects in your eyes

If you have a foreign body in your eye it will likely cause pain, redness, and tearing. You may also feel like there is something in your eye that you can’t remove.

Small objects such as dirt or sand can usually be removed by blinking or flushing your eye with water or eye drops. If the object is stuck and you cannot remove it, you will need to see your doctor.

Chlorine from pools is also an eye irritant that can cause your eyes to become red, especially if you open your eyes underwater.

Alcohol abuse

Alcohol abuse can cause your eyes to become bloodshot or red because alcohol dilates the blood vessels in your body including the ones in your eyes.

Alcohol abuse can also lead to more serious problems such as vision loss, optic nerve damage, and even blindness. If you think you might have a problem with alcohol, please seek help from a medical professional.


Smoking cigarettes can cause your eyes to become red and bloodshot due to cigarette smoke being an irritant.

Smoking also increases your risk of developing cataracts, macular degeneration, and other serious eye problems.

If you smoke, quitting the habit will improve your overall health and the health of your eyes. Smoking marijuana can also cause red eyes due to it dilating the blood vessels in your eye which causes them to appear red.

Eye drops

Eye drops causing red eyes may seem antithetical but it is actually a common problem.

If you use whitening eye drops too much or incorrectly, it can cause a medical condition called rebound hyperemia which is when your blood vessels dilate in response to the artificial moisture in the eye drops.

Rebound hyperemia can cause your eyes to become red and irritated so it is important to follow the directions on the eye drop bottle and not use them more often than directed.

How do you treat red eyes?

There are a few different treatment options for red eyes depending on the underlying cause although your eye may produce natural tears to try to fix the condition and it often works.

If your red eyes are due to allergies, you can try using over-the-counter antihistamines or artificial tears (eye drops) to help relieve your symptoms while also avoiding the allergen that causes them.

If you have conjunctivitis caused by a viral infection, there is not much that you can do except wait for it to run its course.

However, you can try using over-the-counter artificial tear drops or a warm water compress to help with the symptoms. If you have pink eye due to a bacterial infection, you will need to see your doctor for antibiotics.

You can also use artificial tears or warm water compresses to help with the symptoms by placing them on the affected area(s) for a few minutes at a time.

If you have any other underlying cause of your red eyes, you need to seek medical attention for a medical diagnosis from your doctor.

When do I need to see my doctor about red eyes?

There are certain times you may need to see your doctor or ophthalmologist, which is an eye specialist doctor.

You need to see your doctor if your red eyes are accompanied by severe eye pain, vision changes such as halos or blurred vision, headaches, nausea, vomiting, eye discharge, swelling, light sensitivity, or if there is an object in your eye you can not get out. If you are unable to keep your eye open you need to also seek medical attention.

See your doctor if over-the-counter treatments are not working or if your symptoms persist or are getting worse as most cases clear up on their own.

How are red eyes prevented?

There are a few things that you can do to prevent red eyes such as:

  • Washing your hands regularly and avoiding touching your eyes
  • Avoiding triggers such as smoke, dust, pollen, etc. if you have allergies
  • Limiting your alcohol consumption
  • Following the directions on eye drop bottles
  • Taking breaks from staring at screens and limiting your screen time
  • Getting a regular comprehensive dilated eye exam
  • Removing eye makeup properly
  • Washing your eyes and keeping your eyelids clean
  • Keep your contact lenses clean if you wear them and do not use them for longer than recommended


Red eyes can be a sign of many different issues ranging from allergies to more serious eye conditions such as glaucoma and an eye infection.

There are a few different ways that you can treat red eyes depending on the underlying cause, however, most cases clear up on their own.

You need to see your doctor if your red eyes are accompanied by pain or other symptoms and if you have persistent symptoms longer than normal.

There are also a few things that you can do to prevent red eyes such as washing your hands regularly, avoiding touching your eyes, and avoiding any allergens which could irritate your eyes along with several other simple things.

If you have any more questions about why your eyes are red or how to treat them, please talk to your doctor, health care provider, or ophthalmologist.

References and sources:


Cleveland Clinic 

Mayo Clinic 

medically reviewed and fact checked