Where is the cornea of ​​the eye

Many people have heard about the story of some people donating their corneas after death. People only know that the cornea can restore sight to the blind and is a very important part of people's eyes. However, many people do not know where the cornea is exactly. Some people even think that the cornea should be located at the corner of the eye. In fact, this is not the case. The cornea is a membrane covering the eye. Let us understand where the cornea is.

The cornea is a transparent membrane at the front of the eye. The cornea is completely transparent, located in the front of the eyeball, and is transversely oval in shape. The cornea has very sensitive nerve endings. If foreign objects touch the cornea, the eyelids will close involuntarily to protect the eyes.

The cornea is completely transparent, located in the front of the eyeball, and is transversely oval in shape. The cornea, which accounts for 1/6 of the outer wall of the eyeball, and the sclera together constitute the outer wall tissue of the eyeball. The cornea is a convex, highly transparent substance at the front of the eye that covers the iris, pupil, and anterior chamber and provides most of the eye's refractive power. Combined with the refractive power of the lens, light can be accurately focused on the retina to form an image. The cornea has very sensitive nerve endings. If foreign objects touch the cornea, the eyelids will close involuntarily to protect the eyes. In order to remain transparent, the cornea has no blood vessels and obtains nutrients and oxygen through tears and aqueous humor.

Our eyelids will blink without our awareness, and every time we blink, tears will form a thin tear film on the surface of the cornea to protect the "lens". Since the cornea is transparent, there are no blood vessels on it. Therefore, the cornea mainly obtains nutrients from tears. If the nutrients contained in the tears are insufficient, the cornea will become dry and its transparency will decrease. The cornea also gets oxygen from the air, so many people feel their eyes are a little dry after waking up. The composition of tears is very similar to the liquid part of blood. Oily components such as cholesterol and lecithin are attached to the surface of the cornea to inhibit the evaporation of water. The enzyme called lysozyme has a bactericidal function and can protect the cornea from infected bacteria that come into contact with the outside air.