What and Why?
Your eye is covered with a special kind of skin called conjunctiva, which is very thin, smooth, sensitive and transparent, revealing the white fibrous eyeball and providing a good optical surface to the cornea. It starts at the margins of your eyelids, and drapes in one continuous and closely fitting vacuum-moulding across their insides and the front half of your eyeball, with deep folds into the farthest recesses of the space between them.
This elaborately moulded conjunctiva is flexible and its outside surfaces are very slippery; lubricated by a continuous thin film coating of tears and nourished from inside by a tracery of fine blood vessels all over the eye and both eyelids. This arrangement seals your eye from the outside yet enables it to move freely inside your eyelids, whether open or closed, by sliding two conjunctival surfaces over each other.
There are snags however. The outside surface of the conjunctiva is like the inside of an irregularly shaped bag, with its neck open to the air outside your eyelids. This bag is empty but for the lubricating film of tears, and is kept at body temperature. This makes it a very comfortable incubator for the airborne germs that find haven there. So the tears also have an antiseptic function and, with the assistance of immune factors available from your circulation, patrol the bag continuously to prevent microbial growth.
During any prolonged period of eye closure debris from this patrolling function accumulates as a harmless sticky pus-like blob that you can rub from the inside corner of your eye. There tends to be more of it when you are unwell because the patrolling is clumsier and less efficient; more effort is required to achieve the same result. Occasionally even in health you need to make a greater effort than usual to subdue a correspondingly larger or more aggressive colony of bacteria.
In this way you may often have more than usual of the familiar debris, but runnier and less sticky for having less time to dry out. So long as your conjunctiva is still white and comfortable you should regard this as a healthy variation of the normal pattern, not as a disease.
If a microbe becomes established, watery tears will run from an irritable conjunctiva, reddened by inflamatory swelling of the blood vessels underlying it. If the microbe is a virus as is more usual, your nose will become involved if it isn’t already (see Colds): otherwise, suspect that a germ is responsible. The tears are teeming with microbes in either case and highly infectious. They may eventually settle down to the more purulent character reminiscent of health, but the eye will still be pink and feel gritty.
Chemical irritation, smoke, or a speck of dirt in the eye will produce a very similar response but the cause is then more obvious. Continual exposure to tobacco smoke can make your eyes chronically irritable and dry.
Chronic infection is rather different and affects your eyelid margins rather than your conjunctivae. They become thickened, encrusted with fine scales, dusky pink and irritable. Your eyes feel tired and water easily.
What can I do?
Advice to maintain and maximise health
1. Never use hot water or soap on your face unless it really is dirty. The skin of your eyelids is particularly sensitive to these, which can make them chronically irritable.
2. Cold water is a powerful tonic if sprayed on your closed eyelids until they just begin to ache. Then massage the eyeballs by rolling them under firm finger pressure through closed eyelids. This procedure is helpful in any chronic eye complaint.
3. Avoid tobacco smoke as much as you can — your own and other people’s.
4. Rue tea makes an excellent eye-wash for general purposes: fresh flowers are the most potent. Euphrasia (Eye-bright) drops are also available in herbal or homoeopathic potency.
5. A fresh milk eye-wash is easy to organize quickly if chemical gets in your eye. It blots up most of them and relieves chemical irritation safely and well. See a doctor within a few hours if it fails to.
6. Pain from a welding accident, or after any fragment has hit your eye at high speed, may mean that debris is embedded in your cornea or under your conjunctiva. You will need to see a specialist eye doctor. Bandage a patch over your eye to protect it and attend a hospital Accident and Emergency Department in the first place.
7. If your eye remains white but becomes pussy, simple bathing with tepid salty water is safe while you await developments and is usually enough to get it better. If it becomes red and runny during a cold, in the first place treat the cold.
8. For any other pain or redness of your eye, or chronic pussy discharge from it, see your doctor.