About maintaining eye health and what harms it

Whoever is concerned about maintaining the health of the eye must protect it from dust, smoke and air blows that have gone beyond the limits of moderation in the sense of heat and cold, protect it from sharp, cold and simoom-like winds. You should not look at the same object for a long time without turning away. Prolonged crying is a good eye cleanser. You should look less at small objects, unless sometimes for the sake of exercise. Sleeping on the back of your head should not be long. Know that too frequent intercourse is one of the most harmful things for the eye, as well as frequent intoxication and gluttony. Sleeping on a full stomach, all thick foods and drinks, and anything that allows steam to rise into the head are also harmful. This includes anything that is spicy, such as leeks and sweet clover. Anything that dries excessively is also harmful. This includes a large amount of salt and everything that produces abundant vapors, such as cabbage and lentils. What is mentioned in the chapters on simple medicines and is similar to what is mentioned above also harms the eye. You should know that sleeping too long and staying awake for too long are very harmful to the eyes; moderation in both is more favorable.

Among the remedies, the use of which is beneficial for the eye and preserves visual power, are those prepared from antimony glitter and tutia, such as, for example, various remedies from tutia, boiled with the juice of marjoram and fennel. Constantly lubricating the eyes with an infusion of anise has an amazing effect and is extremely beneficial, and also a lotion made from sweet pomegranate juice and a lotion prepared from the juice of both types of pomegranate, squeezed with pulp and boiled with honey in a baking oven, are also surprisingly useful, as you will learn about this in your place. Remedies that cleanse and sharpen the eyes include immersing yourself in clean water and opening the eyes under water.

As for things harmful to vision, these include some actions and movements and some foods and their use. Such actions and movements include everything that dries, for example, frequent copulation, prolonged examination of shiny objects, excessively long reading of too small a letter. However, if this is done in moderation, there will be no harm. Delicate work and sleeping on a full stomach immediately after dinner are also harmful; on the contrary, one who has weak eyesight should wait until he has digested the food, and then go to bed. Any overflow is harmful to him and everything that dries out his nature is harmful. Anything that muddies the blood is also harmful to him, be it salty or spicy things and others. And intoxication is harmful to him, but vomiting is useful because it cleanses the stomach. But, on the other hand, it is harmful to him, because it sets in motion the matter of the brain and drives them into the eyes. If vomiting is necessary, it should be induced after eating and carefully. Frequent bathing in the bathhouse is also harmful, as is excessive sleep, excessive crying, excessive bloodletting and, especially, the constant use of blood-sucking cups.

Foods that are harmful to the eyes are salty, caustic and steamy, causing pain in the mouth of the stomach: leeks, onions, garlic, basil, ripe olives, dill, cabbage and lentils. To properly dispose of food means to take it in such a way that indigestion does not occur and the formation of vapors from it does not increase, as will be explained in its place.