Red eyes, also known as bloodshot eyes, are a common condition that most often occur when the blood vessels on the surface of the eyes become swollen and inflamed.

There are various causes of red eyes, ranging from environmental irritants to underlying health conditions. Understanding the causes of red eyes is crucial in determining the appropriate treatment for the condition.

Allergies

Allergies are one of the most common causes of red eyes. When the eyes come into contact with allergens such as pollen, pet dander, or dust mites, the immune system may respond by releasing histamine, causing inflammation and redness.

Allergic conjunctivitis often presents with itching, watering, and swelling of the eyes as well.

Dry eyes

Dry eyes occur when the eyes cannot produce enough tears or when the tears evaporate too quickly. This often leads to redness and irritation of the eyes.

Some of the causes of dry eyes include hormonal changes, aging, certain medications, and autoimmune conditions such as Sjogren’s syndrome.

Bacterial or viral infections

Bacterial and viral infections such as conjunctivitis or pink eye can lead to red eyes. These infections are highly contagious and often present with symptoms such as eye discharge, itching, and swelling of the eyelids.

Bacterial conjunctivitis can be treated with antibiotics, while viral conjunctivitis usually clears up on its own after a few days.

Eye strain

Extended periods of reading, using the computer, or watching TV can lead to eye strain and subsequent redness. This may be due to the overuse of the muscles that control eye movements, leading to fatigue and discomfort.

Red eyes caused by eye strain can be relieved by taking regular breaks and practicing good eye hygiene.

Contact lenses

Wearing contact lenses that are improperly fitted or not cleaned regularly can cause red eyes. This is because contact lens wear can lead to irritation and scratches on the surface of the eye, leading to inflammation and redness.

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Proper contact lens care and maintenance is important for preventing red eyes.

Injury

An injury to the eye can cause redness and swelling. This may be due to trauma to the eye or surrounding structures, leading to inflammation and bleeding. Some of the common causes of eye injuries include accidents, sports injuries, and falls.

Seeking immediate medical attention is crucial in treating eye injuries.

Exposure to irritants

Exposure to irritants such as smoke, fumes, or chemicals can cause red eyes. This is because these irritants can cause irritation and inflammation of the eyes, leading to redness and discomfort.

Wearing protective eyewear and avoiding exposure to irritants can help prevent red eyes.

Glaucoma

Glaucoma is a condition that affects the optic nerve and can lead to vision loss if left untreated. Some types of glaucoma can cause redness of the eyes.

This is because the increased pressure in the eye can lead to a buildup of fluid and subsequent inflammation. Treatment of glaucoma usually involves prescription eye drops or surgery.

Uveitis

Uveitis is a condition that affects the middle layer of the eye, called the uvea. The condition can cause inflammation and redness of the eye. Uveitis can be caused by infections, autoimmune conditions, or exposure to toxins.

Treatment usually involves prescription eye drops or systemic therapy.

Scleritis

Scleritis is a rare condition that affects the white part of the eye, called the sclera. The condition can cause redness, pain, and vision loss. Scleritis can be caused by autoimmune conditions such as rheumatoid arthritis or infections.

Treatment of scleritis usually involves prescription eye drops and management of the underlying condition.