The conjunctiva is the clear membrane that covers your eyeball, whereas the cornea is the transparent tissue that covers your iris and pupil. — MCT
Conjunctivitis is also called pink eye.
It is an infection or inflammation of the transparent membrane that lines your eyelid and eyeball, which is called the conjunctiva.
The pink colour is caused by the small blood vessels in your normally-white conjunctiva becoming swollen and irritated.
It can also become red in colour.
Conjunctivitis is usually caused by a viral infection.
Sometimes, it can also be caused by a bacterial, fungal or parasitical infection; an allergy to something you put in your eye; or something that got into your eye by accident.
Even smoke, dust and chemicals in the air can cause conjunctivitis.
Conjunctivitis usually begins in one eye and rapidly infects the other.
I’m guessing what you mean is, why is conjunctivitis so contagious?
An infectious condition is one that is caused by an infectious agent, like viruses, bacteria, fungi or parasites.
A contagious condition is one that spreads through direct contact between humans.
As a rule, all contagious conditions are infectious, but not all infectious conditions are contagious.
The kind of conjunctivitis you get from a microorganism is both infectious and very contagious.
This is because the droplets from an infected person’s eyes can get anywhere.
If you touch or shake hands with the person, you may get it.
If you touch objects or surfaces (like tables) with the microbes on it, then touch your eyes, you may also contract it.
That is why you have to wash your hands often.
No.
The most common conjunctivitis symptoms are:
- Redness in one or both eyes
- Itchiness
- A gritty or sandy feeling in the eye
- Eye discharge that forms a crust during the night that may prevent your eyes from opening easily in the morning
- Tearing easily
- Sensitivity to light (photophobia).
But it won’t affect your vision unless your cornea is involved.
If your cornea becomes involved in the infection, it becomes known as keratitis.
Your cornea is the clear tissue that forms the front of your eye, covering your iris and pupil.
Keratitis may be caused by an infection or an injury (like if you wear your contact lenses too long or if you get an eyelash that is poking it).
With keratitis, you may experience these symptoms:
- Eye redness and actual pain
- Excessive tears or discharge from your eye
- Difficulty in opening your eyelid because of pain
- Blurred and even decreased vision (yes, your vision can be affected, unlike conjunctivitis)
- Sensitivity to light
- The feeling that something is inside your eye.
Wearing contact lenses appropriately is not dangerous.
However, it can be dangerous if you misuse them.
If you sleep with your contact lenses on just because you think you want to see clearly when you wake up at night, or because you are too lazy to take them off, then your risk of eye infections and injuries will increase.
Keratitis is an especially worrying condition.
If you swim with contact lenses and do not protect your eyes with the appropriate goggles, or if you shower with your contact lenses, you are at higher risk of it.
If you do not disinfect your contact lenses properly, you are also at higher risk.
Experts generally recommend not wearing contact lenses for more than eight hours a day.
If you want to swim with contact lenses, make sure you always wear protective goggles as well.
Not in most cases, but blindness is definitely a potential complication of keratitis.
Other complications include:
- Chronic corneal inflammation and scarring
- Chronic or recurrent viral infections of your cornea
- Corneal ulcers
- Temporary or permanent reduction in your vision.
Conjunctivitis treatment is usually symptomatic.
If you wear contact lenses, you will be advised to stop wearing them until your conjunctivitis clears up.
As conjunctivitis is mostly caused by a virus, you won’t need antibiotic eye drops (which are only effective for bacteria).
In fact, they may even cause more inflammation.
You just need to let your eye heal on its own, which takes around two to three weeks.
If your conjunctivitis is caused by an allergy, then the doctor may prescribe antihistamine eye drops.
The treatment for keratitis will also depend on the cause.
Antibiotic eye drops are needed for bacterial keratitis.
If your cornea has been permanently damaged by the keratitis, then it is possible you may need a corneal transplant.
Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, email starhealth@thestar.com.my. The information provided is for educational and communication purposes only, and it should not be construed as personal medical advice. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
