What are the different layers of eye tissue?
Human eye has three layers of eye tissue: fibrous layer, vascular layer and retina. Each of these layers performs a different function in the help of the human to be seen or in the eye, and also forms a place for the muscles to which it is to be attached. The vascular layer protects part of the eye. The fibrous layer of eye tissue allows the light to enter the oms and control how much light comes into it. The retina is part of the eye that allows you to see.
The fibrous layer has two different parts. When one sees white eyes, in fact, it is looking for a glass, part of the fibrous layer of eye tissue. Sclera is white, opaque and hard. It not only forms the shape of the eye, but also provides an eye muscle anchoring space. This layer helps protect the rest of the eye. The cornea is the most exposed part of the eye and is filled with pain receptors. It is transparent and contains no blood vessels, but is able to regenerate when it is damaged. Because it has no blood vessels, it can be transplanted from a person to a person with a small or no risk of rejection.
Most of the eye are found in the vascular layer of eye tissue. The pigment is used to absorb scattered light to prevent the confusion of sight. The choroid part of the vascular layer contains blood vessels that nourish the eye. Another layer, a ciliary body, forms a strong tissue around the lens. The ciliary body usually contains muscles that control the shape of the lens.
Iris is part of the vascular layer of eye tissue that determines the color of the person's eye. With the exception of Albinos, each person has only a brown pigment, regardless of eyes color in the eyes. People with brown eyes have a pigment as on the back of Iris and in the body of Iris and those with hazel eyes have less pigment in the iris. If a person only has a pigment only on the back of the iris, the light can worry when it passes through a colorless part, allowing another person to see only a certain light wool. The result is a variety of different colors of the eyes that people can have, including shades of blue andGreen.
The pupil controls the amount of light that enters the eye. Muscles in the contract on the iris and the expansion of the pupil according to the voltage and the amount of light in the vicinity. In a darkened room, when a person is afraid, or when he focuses on object far, the pupil spreads to release more light. If a person is in a bright room or focuses on a nearby object, the pupil becomes a reduction in the amount of light that enters the eye. Stress can also cause the pupil to dilate.
eye tissue known as the retina - part of the eye that allows you to see - is sepacked into two layers. The outer layer, a pigmented layer, absorbs light and also removes damaged and dead photoreceptor cells. It also serves to recycle the product of vitamin A, which needs to be seen. The inner layer, the nueral layer, contains photoreceptors and other cells that allow one to see. When the light hits them, they generate a signal that is sent to the brain and is translated as vision.