Today my topic is human eye. As we all know that human eye is the important part of our body. Without Eye we cannot see. We can say that without eyes we are not able to do anything. And we can not work in our daily life.today i will tell you about the structure of eye. It's parts, and also its disorders. and how we can use lenses, and type of lenses we can use to correct our sight.

• Human eye structure is very unique. Human eye is consists of complex structure. It is in the form of a ball.Human eye has three main layers which are as under:
• Outer layer
  Choroid
  Inner Most Layer.

Outer layer:
it is white, tough and muscular layer which is also known as Sclera. The main function of the outer is to cover the outside. And anterior is transparent and bluging to make cornea.
Iris:
Iris is the colored portion in the center. Pupil is the small hole in the center of the iris.
Function of the Pupil:
The main function of the pupil is to control the amount of light which is directly enter into the eye. When Light is dim it is open and when Light is bright than it is close.
Lens:
Behind the pupil. It Focus image on retina.It is held by ciliary muscle and suspensory ligaments. A fluid is present is the lens and cornea. The function of the fluid is to cornea and lens.
Choroid:
The second layer is choroid. Choroid is vascular layer of eye. The main function of the choroid is to nourish the eye.

Inner Most Layer:

            The Inner most layer of eye is Retina. Retina is composed of Neuron called Rods and Cones.

Rods: For Perceive dim light they give us colorless image

Cones: The visualizing the color.