Most people suffer from red or bloodshot eyes at some time or another. They occur when blood vessels near the surface of the eye become irritated, causing them to become enlarged and dilated. While red eyes are a common condition which generally does not “raise a red flag” to signal anything serious, the eyes are red for a reason, and there is a variety of reasons which may be responsible. Depending on the underlying cause, red eyes can be associated with other symptoms including burning, itching, watering, discharge, swelling of the eyelids and sensitivity to light.


Dry Eyes

A common cause of bloodshot eyes is dry eye syndrome, which occurs when there are not enough natural tears to keep the front part of the eye lubricated. When the eye becomes dry, it also becomes very red and irritated. Dry eyes may be the result of hormonal changes in the body, chronic medications, lack of sleep, wearing contact lenses for too long or extended periods of staring at computer screens. Lubricating eye drops, either bought over the counter or recommended by your optometrist, may be helpful. Take regular breaks from computer work and follow your optometrist’s instructions on contact lens wear. Don’t forget to blink!

Pink Eye

Conjunctivitis, commonly called “pink eye” is an inflammation or infection of the clear, protective layer that coats the front part of the eye. It may be bacterial or viral, causes the eyes to be red and is often associated with a discharge. Although uncomfortable, it is usually not serious, but is contagious so should be treated with the correct eye drops prescribed by a doctor.


Blepharitis is inflammation of the eyelids which occurs when the oil glands at the base of the eyelids become clogged, leading to irritated red eyes, swollen eyelids, a gritty or burning sensation or crusting of the eyelids. While uncomfortable and unsightly, it does not cause damage to the eyesight. The exact cause is unknown, and it is often difficult to treat. If it does not improve despite good eyelid hygiene, medication may be prescribed.


Uveitis, an inflammation of the eye’s uvea, can cause redness, pain, blurry vision, floaters, and light sensitivity. Symptoms of this condition can occur suddenly and get worse very quickly. Unless treated promptly, it can lead to complications.

Frequent Use of Eye Drops

Surprisingly, frequent use of eye drops to reduce redness of the eyes can actually make the eyes appear even redder. The chronic use of these eyedrops can cause “rebound dilation” of the blood vessels in the eyes, causing the eyes to appear more bloodshot. Consult your optometrist to determine the underlying cause of the redness and for the recommendation of appropriate eye drops to use.

Contact Lens Wear

Wearing contact lenses can sometimes cause eye redness. If you experience discomfort while wearing contact lenses, discuss this with your optometrist who may suggest suitable eye drops for contact lenses or seek alternative solutions.


Redness sometimes occurs with an eye injury. When you injure your eye, blood vessels inside the eye enlarge and dilate to bring blood and cells to heal and repair the injury. Visit your optometrist to assess the extent of the injury and ensure that the eye is not damaged.


Red eyes associated with burning and itching are often caused by allergies. They generally occur at specific times of the year or in particular situations. The eyes become red because the blood vessels in the front part of the eye dilate and become larger. Fluid accumulates and causes swelling. Standard allergy treatments can help reduce eye redness, but there may be specific treatments based on the situation.

Computer Vision Syndrome

Red, dry eyes result from a lack of moisture to the eyes, which is replenished by blinking. Blinking is one of the fastest reflexes of the body. However, people tend to blink about half as much as normal when they are working on a computer. Try to reduce redness by blinking more often and looking up from the screen at regular intervals. Artificial tears can replenish tears and provide relief.


Smoking a cigarette releases several harmful chemicals including formaldehyde, ammonia, and hydrogen sulfide which are irritating to the sensitive membranes of the eyes, causing inflammation and red eyes. Smoking can also increase the risk of cataracts., a cloudiness in the lens of the eye.

Lack of Sleep

If you don’t get enough sleep, your eyes may show it. Losing sleep tends to increase the retention of blood and fluid around the eyes, making them appear puffy and red. Lack of sleep can also lead to dry eyes which exacerbates the redness. Eyes need a constant supply of tears to function properly, which is why blinking is so important. Not allowing the eyes to close for a long night prevents eyes from getting proper fluid circulation. Your eyes need fluid in order to clean and renew. Staying awake too long is not a good idea for overall eye health.


Alcohol can cause vasodilation, causing the vessels on the white part of the eye to become larger and more visible. Also, alcohol is dehydrating and can causes the eyes to appear red and tired.

Corneal Ulcer or Infection

The cornea does not have blood vessels, so if it becomes infected, nearby blood vessels become enlarged and swollen as cells rush in to help fight the infection. These cells can cause visible redness. Corneal ulcer treatment needs to be prompt and aggressive in order to prevent potential vision loss. Treatment usually involves antibiotics as well as antiviral or antifungal medications or steroids.

Subconjunctival Hemorrhage

A subconjunctival hemorrhage causes the white part of the eye to become completely red. It occurs when one of the blood vessels bursts or breaks underneath the conjunctiva, the transparent, clear tissue that covers the white part of the eye. The blood has no place to go, so it spreads out beneath the conjunctiva. A subconjunctival hemorrhage can look unsightly, but it is usually no cause for alarm especially if there is no pain or visual changes. The cause of a subconjunctival hemorrhage is not always known, but some cases have been linked to coughing, straining, or using blood thinners. 

Occasionally subconjunctival hemorrhages have been linked to high blood pressure or a bleeding disorder. Because the hemorrhage is not dangerous, no treatment is needed and symptoms usually disappear within a week or two. If the cause is high blood pressure or a bleeding disorder, you may need to consult your doctor for treatment.

Acute Angle-Closure Glaucoma

Sometimes a red eye can signal a serious condition. One very serious eye condition that may cause red eye is acute angle-closure glaucoma, which is a medical emergency that must be treated immediately. It occurs when the fluid pressure inside the eye rises quickly. This type of glaucoma usually occurs in only one eye, causing sudden redness in the eye, severe eye pain, and blurred vision. Visit your optometrist as soon as possible.


Episcleritis is an inflammation of the thin clear layer of tissue that lies between the conjunctiva and sclera. Episcleritis causes mild eye pain and irritation along with eye redness. Sometimes the eyes become tender to the touch. Although it may go away on its own, topical steroids are often needed.


In most cases, red, bloodshot eyes will clear up on their own within a few days. 

If you are experiencing bloodshot eyes due to allergies or environmental irritants oral antihistamines or over-the-counter eye drops may help. 

Either the gentle heat of a warm cloth or an ice pack helps reduce irritation and redness of the eyes. 

Rinsing the eyes with warm or cool water can irrigate and cleanse your eyes without harming them. 

Take a break from your smartphone or computer. 

Stay hydrated by drinking enough water. 

Artificial tears are a simple solution which help flush out irritants as well as alleviating dryness. 

Fatty acids found in fish, nuts, and leafy vegetables can be beneficial to dry, red eyes. 

If the condition persists or is associated with symptoms such as pain or a sudden change in vision, schedule an appointment with your optometrist.