What is red eye?
“Red eye” is generally used to describe red, irritated and bloodshot eyes. It is often times caused by swollen or dilated blood vessels on the sclera (the white outer surface of the eye).it can appear suddenly or develop over time.
It may appear bright red and completely cover the sclera or it may appear as wiggly red or pink lines across the sclera.
What are the causes of red eye?
Common causes of red eye include
1. Conjunctivitis: It is sometimes called “pink eye”. It is one of the most common eye infections especially among children of school age. It results from infection of the conjunctiva (the thin, transparent membrane that covers the sclera and lines the eyelids) which causes its blood vessels to become irritated and swell, giving the eye a red or pink appearance.There are different types of conjunctivitis, so, there are different ways of treatment.
2. Dry eyes: This is also called “dry eye syndrome” and it results from an inability of the tear glands to produce either a sufficient quantity or quality of tears to properly lubricate and nourish the eyes. Chronic cases cause the surface of the eye to become inflamed and irritated, making the eye look red.
3. Allergy: The immune system reacts to a foreign substance such as dust, chemicals in make up or contact lens solutions etc by releasing histamine to fight off the allergens. Histamine causes the blood vessels in the eye to enlarge, making the eyes red and watery.
Other causes are
4. Contact lenses: Contact lenses which are not properly cared for or which are left in the eyes for too long cause an accumulation of irritating surface deposits and microbes on the eye.
Contact lenses also reduce the amount of oxygen reaching the cornea and can restrict normal tear flow production especially if they don’t fit properly. This can worsen dry eye syndrome.
Red eyes while wearing contact lenses could signify a serious eye infection. If this is experienced, the contact lenses should be removed immediately and an eye doctor should be seen immediately.
5. Computer vision syndrome: Staring at a computer screen for too long can result in red, burning and tired eyes, because we blink less when working ata computer, which dries out the surface of the eye.
6. Eye injury: Trauma or injury to the eye can cause red, bloodshot eyes which may be accompanied by a subconjunctival haemorrhage.
In response to injury, blood vessels in the eye dilate to allow more blood flow to the injury site for quicker healing. This dilation (and sometimes) breakage of blood vessels on the eye is the cause of the redness.
7. Corneal ulcer: This is the result of untreated eye infection or eye trauma. It is a potential threat to sight and should be treated as an emergency. Other symptoms are eye pain, reduced vision and eye discharge.
8. Ocular herpes: This is also called eye herpes. It s a recurrent viral infection, caused by the type1 Herpes simplex virus. Other symptoms are swollen eyes, eye pain, watery discharge and light sensitivity.
If left untreated, it can cause scarring of the cornea, and in some cases, a corneal transplant may be required to restore vision.
9. Uveitis: This is an inflammation of the uvea (the middle layer of the eye). This results in red eyes, light sensitivity and visual disturbances such as floaters and blurry vision.
Uveitis may be caused by eye infections, eye injury or trauma, or a systemic autoimmune disorder but in many cases, the cause is unknown.
10. Glaucoma most times is gradual and asymptomatic when it first develops. However, a sudden onset of painful, bright red eyes, accompanied by haloes around lights and vision loss may point to an acute condition that demands urgent medical attention.
11. Whitening eye drops: Eye drops marketed for red eyes have chemicals that shrink the blood vessels on the surface of the eye to reduce the redness.
Regular long term use can cause the redness to worsen after the drops wear off – this is called rebound hyperaemia.
12. Cold and flu can cause bloodshot and puffy eyes. The red eyes result from a sinus infection or blocked sinuses.
13. Pregnancy: Hormonal changes in pregnancy can cause the eyes to become red or bloodshot, dry, itchy and sensitive to light. These problems are usually temporary and resolve within weeks or months after childbirth.
14. Smoking: Tobacco smoke is a toxic eye irritant that can cause dry, red and itchy eyes. THC, the major psychoactive substance in marijuana, causes significant dilation of blood vessels on the eye, producing eye redness that can last several hours or even longer.
15. Alcohol: Alcohol reduces oxygen to the red blood cells, causing blood vessels to clump together. The result is a ruddy complexion and red, bloodshot eyes.
16. Environment and work place hazards: Extremely dry air, dust, smoke and excessive sun exposure are known eye irritants that can cause red eyes and other symptoms.
Protective eye wear such as safety glasses should be used to prevent foreign objects from getting into the eye.
17. Lack of sleep can cause red, puffy eyes with dark circles around them. Rubbing sleepy eyes aggravates the redness.
Can red eyes be prevented?
The following measures can help prevent red eyes
1. Do not rub your eyes. Irritants on the hands or fingers can worsen the redness and irritation.
2. Practice good hygiene when wearing contact lenses.
3. Speak to your doctor about allergy medications to help keep allergies away.
4. Every 20 minutes, look away from the computer and focus on an object 20 feet away from you for at least 20 seconds. This is the 20-20-20 rule.
5. Have an eye examination to rule out more sinister causes of red eye.
6. Don’t overuse whitening eye drops.
7. Wear swim goggles when swimming and never swim with contact lenses.