1. Basic structure of eyeball
Eyeball is the mainly organs for sight, it is like ball, and it is located in eye socket.
Exophthalmoses consist of 3 parts, inside, middle chain.
Outside chain is made of cornea and sclera
Cornea is the crystal part in the front of eyeball, it is like a plate and a concave-convex lens, the cornea and sclera connect at edge, the thickness of cornea is not the same in different areas, but the cornea has rich neural crests, and it is hypertensive. The light get into eyeball through cornea, so it is the rntry of information.
Sclera is made of compact dense collagen fiber organization. It is not crystal, but it is ivory, hard and tough.��it has a few of blood vessels, nerves, fiber cells and pigment cells and so on.
Middle chain is called tunicae uveae��it is made up of rich pigment and blood vessel. It contains three parts, iris, ciliary body and choroids.
Inside chain is retina, which is a crystal chain; it is the first stop when the nerve information appears��It has fine structure and rich metabolize function and physique function. All the information from retina will be sent to brain through optic nerve. it contains lots of pigment structure for iris.
Iris is like a round circle, at the front of tunicae uveae, located in front of lens. In the middle there is a 2.5-4mm-round hole called pupil.
There is lacuna between a atria and a posterior chamber and vitreous body, they communicate with each other through pupil. The iris is made up of iris stroma and iris epidermis.
Iris stroma��it contains lots of pigment cells and loosen connective tissue. There are 2 kinds of pigment cells in iris stroma. Pigment cells contain lots of pigment grains while the other one distributes in the form of group, and it is smaller and contains pigment grains.
The blood vessels of iris distribute in the form of radial, its features are thick ectoblastic, thin muscular coat. In addition, there are not any holes in endodermis so it has the function of blood-eye barrier.
Iris epidermis: it belongs to the blind area of retina, and it is made up of 2 chains of pigment cells. It contains melanin granule, the epidermis cell and retina cell are similar.
There are 3 chains of structures in iris tissue chain:
1. Front chain connects to iris epidermis;
2. Iris stroma is the loosen connective tissue of blood vessels and pigment cells.
3. Iris epidermis is made up of 2 chains of pigment epidermis cells.