Red eyes occur when small blood vessels found on the surface of the eye become enlarged and engorged with blood. This occurs due to insufficient amount of oxygen being delivered to the cornea or the tissues covering the eye.

There is usually no reason to be concerned, but when combined with eye pain or impaired vision, for example, it can indicate a serious medical problem.

Causes of red eyes

Conjunctivitis

It is an infection that includes swelling and irritation of the conjunctiva (a thin transparent membrane that lines the eyelid and the front part of the eyeball). An infection of the conjunctiva irritates the blood vessels causing them to swell.

Viruses cause up to 80% of all cases of pink eye and it is highly contagious . The infection is usually spread through direct contact with contaminated fingers or personal items. Conjunctivitis caused by allergies or irritants is not contagious.

Symptoms of conjunctivitis include: itchy eyes, excessive production of tears, redness, light sensitivity, poor vision , and grittiness in one or both eyes.

Corneal ulcer

A corneal ulcer is an injury to the cornea normally caused by bacterial infections. They often appear as a result of an eye injury, trauma, or some other type of damage.

Symptoms of a corneal ulcer may include: red eyes, eye pain, sensitivity to light, mild to severe eye discharge, reduced vision or white spots on the cornea.
People with eyelid disorders, cold sores and who wear contact lenses are at risk of developing corneal ulcers, as the eyes are very susceptible to irritation from contact lenses, especially if they are not used safely, not stored properly or not are properly cleaned.
Other causes of corneal ulcers include: fungi, parasites, viruses, dry eyes, allergies, generalized infection, abrasions or burns to the cornea or Bell’s Palsy.
If not treated properly they can lead to severe vision loss or even the loss of an eye.

Dry eye syndrome

A person who does not produce enough tears, or tears of sufficient quality to lubricate and nourish the eyes properly, is said to suffer from dry eye syndrome. Symptoms include itching or burning eyes, foreign body sensation, pain and redness in the eye, tears excessive, discomfort to the wearing contact lenses, blurred vision, eyestrain, stringy eye discharge, after discomfort of watching TV or reading …

Dry eye is incurable but can be treated.

Subconjunctival hemorrhage

According to the American Academy of Ophthalmology, the subconjunctival hemorrhage occurs when blood vessels of the conjunctiva break and cause blood to leak into the area between the conjunctiva and the white of the eye. When this happens, a small amount of blood collects under the conjunctiva.

Subconjunctival hemorrhages usually appear from a minor injury or trauma to the eye. Even rubbing the eye too hard or coughing excessively might cause bleeding. People who have diabetes, high blood pressure, or who are taking certain medications can also have subconjunctival hemorrhages.

Since they occur on the surface of the eye and therefore do not affect the cornea or the interior of the eye, vision is not affected. It is not painful or causes any strange sensations and usually no treatment is necessary.

Other causes of subconjunctival hemorrhage include: inflammation of the cornea, iris or white of the eye, glaucoma, too much exposure to the sun, dust or other particles in the eye, swimming, drinking or drinking, and environmental irritants or pollutants.

Always remember that if in addition to eye pain you also notice sensitivity to light or blurred vision, what you should do is see your doctor immediately for urgent treatment.