Pink eye occurs when the fine blood vessels on the surface of the eye dilate due to irritation, inflammation, infection, injury, or increased eye pressure. Red eye is generally harmless. However, there are also red eyes that require immediate treatment to avoid damage to vision.
The eyeball has fine blood vessels that function to deliver oxygen and nutrients to the eye cells. When these fine blood vessels dilate due to irritation or inflammation, the eyes will look red. In addition, injury to the eye can also cause these fine blood vessels to burst, resulting in bleeding and redness of the eye.
The cause of red eye can be determined by paying attention to how long the red eye complaint lasts, whether the red eye occurs in one or both eyes, the presence or absence of pain in the red eye, and the presence or absence of visual disturbances.
Causes of Red Eyes
When only one eyeball appears red, this is referred to as unilateral pink eye. This condition can be caused by several things, such as:
1. The entry of foreign objects into the eye
Foreign objects, such as dust, sand, or metal shavings, can enter the eye due to gusts of wind, explosions, or accidents. Symptoms of foreign body entry into the eye can include red eyes, eye pain, and watery eyes.
If this foreign object sticks or sticks to the surface of the eyeball, there can be damage to the cornea that can interfere with vision.
2. Acute glaucoma
Glaucoma usually occurs as a result of a slowly increasing eye pressure over a long period of time. However, in some rare cases, this increase in eye pressure can occur suddenly due to blockage in the anterior chamber of the eyeball.
This condition is called acute glaucoma and causes symptoms such as red eye, eye pain, severe headache, nausea, vomiting, and decreased vision. Acute glaucoma is an emergency condition that requires immediate medical attention.
3. Conjunctivitis and keratitis due to bacterial infection
The conjunctiva is a clear membrane that protects the white part of the eye (sclera) and the inside of the eyelid. When conjunctivitis occurs, which is inflammation of the conjunctiva, the blood vessels around it will dilate and cause the eye to turn red.
One of the causes of conjunctivitis is infection. In conjunctivitis due to bacterial infection, in addition to red eyes, symptoms can also appear in the form of a sticky yellow or green discharge in the eye.
Keratitis is an inflammation of the cornea that often occurs with conjunctivitis. Keratitis can also be accompanied by a more serious condition, namely erosion or injury to the cornea, which requires immediate treatment by a doctor.
4. Subconjunctival hemorrhage
Fine blood vessels in the conjunctiva membrane or in the sclera can rupture and cause blood to collect in the space between the two layers. This condition is known as subconjunctival hemorrhage and usually occurs in people who are taking anticoagulant drugs, people with hypertension, and people who often cough.
A subconjunctival hemorrhage may look serious because the eye looks very red. However, this condition is actually not dangerous. The bleeding will be absorbed by the eye slowly over 2-4 weeks.
5. Inflammation of the sclera, uvea, or iris
The sclera is the white outer layer of the eye. Inside the sclera are the uvea and iris. Each of these layers can become inflamed for a variety of reasons, including autoimmune disease, injury, viral infections, and bacterial infections. Inflammation of these layers can also cause pink eye.
6. Malposition of the eyelids
Abnormalities in the position of the eyelids can cause disturbances in the surface of the eyeball. In a case called entropion, the eyelids fold inward, causing the eyelashes to grow toward the eyeball and scratch the cornea. This condition can cause inflammation or injury to the cornea.
On the other hand, in a case called ectropion, the eyelids fold outward, so that the tears cannot completely wet the surface of the eyeball and eventually the eye becomes dry. This causes irritation to the eyes which causes red eyes.
Causes of Red Eyes in Both Eyes
When pink eye occurs in both eyes, this condition is known as bilateral pink eye. Generally, bilateral pink eye is caused by:
Conjunctivitis due to viral infection
Viruses can cause inflammation of the conjunctiva (conjunctivitis) and cause symptoms such as red eyes, a gritty feeling, and being sensitive to light. In conjunctivitis due to viral infection, the eye will release a watery and clear fluid. This is different from conjunctivitis due to a bacterial infection, where the discharge is yellow or green and thick. Conjunctivitis caused by bacterial or viral infection is a type of infectious eye disease.
Conjunctivitis due to viral infection is generally harmless and will go away on its own within 1-2 weeks. However, this eye infection is very contagious.
Allergic conjunctivitis
In people who have allergies to dust, smoke, perfume, or pollen, exposure to these allergens in the eyes can cause inflammation of the conjunctiva (conjunctivitis).
Symptoms that appear in allergic conjunctivitis are red, watery, and itchy eyes, and swelling of the eyelids. These symptoms generally occur in both eyes. The main way to relieve pink eye and prevent allergic conjunctivitis is to avoid exposure to the triggering substance.
The causes of red eyes vary. Some are emergency and require immediate treatment, some do not need to be treated and can heal on their own.
If your red eye does not heal after more than 1 week or is accompanied by pain in the eye, visual disturbances, or a yellow or green discharge from the eye, consult an ophthalmologist immediately.
Written by:
dr. Irene Cindy Sunur