Red eye is caused by swollen or dilated blood vessels on the sclera, the white outer surface of the eye. A red eye can be accompanied by eye pain, itching, eye discharge, swollen eyes or visual disturbances. In other cases, a red eye may cause no irritation at all.
Common Causes of Red Eye:
- Allergies
Typical symptoms of allergies are redness, itchiness and eye sensitivity. Common allergens that cause these symptoms are dust, pollen, detergents and animal hair. The histamine released by your immune system, causes the blood vessels in your eyes to enlarge, making your eyes become red and watery.
Avoiding known allergens to which you are sensitive or taking medication advised by your doctor such as antihistamine eye drops can help.
- Dry eye syndrome
This occurs when your tear glands produce an insufficient quantity or quality of tears to properly lubricate your eyes. Lubricating your eyes with “artificial tears” eye drops is the usual treatment.
- Conjunctivitis
Conjunctivitis can be caused by a bacterium, a virus or an allergy, and is manifested by redness, swelling and itching in the eyes, as well as increased tear production. It occurs when the conjunctiva — the thin, normally transparent membrane that covers the sclera and lines the eyelids — becomes infected.
There are different types of conjunctivitis — and therefore different ways to treat it — so be sure to visit your eye doctor for correct diagnosis.
- Use of contact lenses
Contact lenses prevent good oxygenation of the eye, causing irritation and redness when used for long hours or during sleep. Compliance with the manufacturer’s instructions and good lens cleaning will protect the eye from inconvenience in the future.
- Computer vision syndrome
When staring at a computer screen for too long, may cause red, burning and tired eyes. One reason is that you blink less when working at a computer, which dries out the surface of your eye. Consider taking frequent breaks while working at a computer.
- Eye injury
Trauma or injury to the eye from minor eye scratches to deep wounds can result in red, bloodshot eyes. Whatever the cause, always visit your eye doctor as soon as possible.
- Cold or flu
Red eyes are common symptoms of a cold or flu which typically are caused by a sinus infection or blocked sinuses.
- Swimming
Chlorine and other pool sanitizers, as well as bacteria found naturally in any type of water, may cause eye redness.
- Lack of sleep
Without adequate rest, the amount of oxygen reaching the eyes decreases, so the blood vessels dilate and the eyes blush. Eye drops will help, but rest is the best solution.
- Alcohol consumption
Alcohol causes dilatation of small blood vessels in the eyes, resulting in more blood passing through them. Reducing the alcohol consumption or using eye drops will reduce the symptoms.