Whether you are really busy with work or pretend to be busy with work, modern white-collar workers spend almost all of their working hours staring at the computer. Throughout the day, the eyes are too tired to open, but also often dry and uncomfortable. What to do? Why not always have a bottle of eye drops next to the computer to prevent visual fatigue! Eyes tired, dry and uncomfortable, point two drops. And wait! The eye drops only momentarily moisturize your eyes, but can not relieve visual fatigue, if used for a long time, the preservatives inside may also let the dry eye disease to find you. 1, dry eye and tears The so-called visual fatigue, that is, many people work for a period of time will obviously feel the eyes dry, some people even feel a burning sensation, foreign body sensation. These are the typical symptoms of dry eye. The so-called dry eye syndrome is the lack of tears in the eyes. Tears are not produced only when you want to cry. Our tear glands produce tears all the time, only in relatively small amounts that go unnoticed by us. When we blink, our eyelids cause tears to form a liquid film – a tear film – on the surface of our eyes so that the surface of our eyes can stay moist. The tear film is not a simple fluid film, it has 3 layers like a sandwich. The surface layer is a lipid layer, which is simply an oil that prevents tears from evaporating; the middle layer is isotonic saline, which contains a variety of cytokines; and the innermost layer is a mucin layer, which is sticky and allows the tear film to adhere to the surface of the eye against gravity. But if you keep your eyes open, this layer of tear film will not last long before it ruptures, and once the tear film ruptures, the surface of the eye loses the protection of the liquid film and is directly exposed to the air, and all kinds of discomfort will come. Under normal circumstances, the eyes will automatically blink when they are uncomfortable, this is because every time we blink 1 time, a layer of tear film will be formed again. However, if you are very focused on solving a work problem or digging a hole on the Internet to fill up a scarf, the number of blinks will involuntarily decrease. Over time, the eyes will naturally become dry and uncomfortable. This is called evaporative dry eye syndrome, is an epidemic in the office. Of course, there are also dry eyes caused by systemic or other eye diseases, which is not discussed in this article. 2, artificial tears to relieve dry eyes There are many ways to treat dry eyes, caused by other diseases, of course, to treat the cause; evaporation caused by strong can be relieved by rest, blinking, increasing air humidity; if still can not relieve, then the most direct way is to supplement the tears – artificial tears, which is the most commonly contacted Eye drops. Artificial tears will simulate the composition and structure of tears as much as possible. The main component is water, or a humectant (to keep the water in the eye as much as possible). Commonly used humectants are chondroitin sulfate, methylcellulose, sodium hyaluronate (sodium vitrate, hyaluronic acid), polyethylene glycol, and so on. They are polymeric materials that can absorb water and have a certain viscosity and pseudoplasticity (they can be shaped into three-dimensional shapes and even support squeezing against other objects, but this state can only be maintained for a while), and can form a film distribution on the surface of the eye. Commercially available artificial tears eye drops will contain one to several of these substances. Some artificial tears also include oil-like ingredients, such as derivatives of phospholipids, in order to simulate the composition of tears. Such artificial tears are closer to real tears and can be dropped into the eye to replenish the lipid composition on the surface of the tear film and enhance the stability of the tear film. Artificial tears should be selected as close as possible to the composition of tears, other eye drops are not suitable as artificial tears, such as antibiotic eye drops, although the composition of the water inside can temporarily moisturize the eyes, but can not maintain, but also in the eye surface abuse of antibiotics to their own increased risk. Some other contain vasoconstrictive drugs, point into the eye, the original congestion of the eye surface blood vessels quickly contracted, congestion appears to be reduced. This is meaningful for eye allergies and the like, but for dry eye or visual fatigue, so that the vascular contraction does not solve the problem, but only short-term stabilization measures. 3, preservatives in eye drops Unless single-use eye drops, most 5 ml or 10 ml bottles of eye drops contain preservatives. The introduction of preservatives allows us to buy relatively cheap eye drops. But even with the preservatives, the Pharmacopoeia of the People’s Republic of China still stipulates that eye drops should not be used for more than 4 weeks after opening. Therefore, please throw away the eye drops 1 month after opening the bottle even if you have not used them all. The preservatives in eye drops do not pose any problems when used in the short term, but there are various adverse reactions when used in the long term. One of them is the toxic effect on the cells on the surface of the conjunctiva and cornea. Remember the tear film “sandwich” mentioned earlier? The innermost layer of mucin is secreted by the cells on the surface of the conjunctiva. Long-term use of eye drops containing preservatives may destroy the “producer” of this important component of the film and worsen dry eye. For dry eye patients who need to use artificial tears for a long time, doctors recommend single-package disposable eye drops because they are preservative-free, but relatively expensive. However, there are exceptions, through the careful design of the eye bottle is possible to isolate the drops and air, each time only one drop, without affecting the remaining, so you can also do without preservatives. 4, point eye drops is also a technical work With the right eye drops, how to point to the eyes is also a technical work. Whether it is to yourself or to others, the first thing is to wash your hands clean. Another important point is not to let the mouth of the bottle touch the eyes, otherwise it will contaminate the eye drops. (1) If it is to others: the correct method is to tilt the other person’s head, use a cotton swab to press the other person’s lower eyelid, and then let him look up, when the gap between the lower eyelid and the eye will be exposed, the other hand to take the eye drops bottle, lift, aim, light pressure, point in a drop can be, more than the eye inside can not be put, and then let him lightly press the inner corner of the eye, close the tear ducts, so that the eye drops in the eye more Stay for a while. (2) If you are ordering yourself: similar action, press the lower eyelid and look upward, but before you can look directly above, put the bottle of eye drops into place and then look upward, but it is still easy to waste a few drops for yourself. If you want to order two or more kinds of eye drops, should be at least 5-10 minutes apart, not then a kind of drops will be the previous kind of eye drops to wash away. (3) eye drops bottles can not be mixed: never put something else into the eye drops bottle, put eye drops location can not be placed in other similar drops, such as point nose, ear, and even what foot, anthritis and so on are separated to put, go back to check the family medicine box of the elderly, often have foot, anthritis mistakenly into the eyes of such things happen.