Question

describe the structure and function of the parts of the human eye.

Answer 1

The eye is our organ of sight.
The eye consist of
cornea
iris
pupil,
lens,
retina,
macula,
optic nerve,
choroid and
vitreous.
Eye is protected inside a bony cavity. It is known as orbit.
The orbit is the bony cavity that contains the eyeball, muscles, nerves, and blood vessels, as well as the structures that produce and drain tears. Each orbit is a pear-shaped structure that is formed by several bones.

The eye is a hollow, spherical structure.It measures about 2.5 cm in diameter. Eye wall is composed of three coats:

1. The outer fibrous coat— sclera, cornea.

2. The middle vascular coat— choroid, ciliary body, iris.

3. The inner nervous coat— retina.

Cornea:

Light enters through the cornea, the transparent outer covering of the eye.Cornea refracts light

Aqueous humour

Helps to maintain shape of the cornea and provides nourishment to the eye

Iris and pupil

Light passes through the cornea and aqueous humor through an opening called the pupil. The size of the pupil is determined by the iris, the contractile ring.

Lens

It focuses the light.Ciliary muscles surround the lens, relaxing to flatten it to image distant objects and contracting to thicken the lens to image close-up objects.

Vitreous humour

The vitreous humor is a transparent watery gel that supports the eye and allows for this distance.

Retina

The innermost coat of eye is retina.When light strikes the retina, two types of cells are activated. Rods detect light and dark and help form images under dim conditions. Cones are responsible for color vision. The three types of cones are called red, green, and blue, but each actually detects a range of wavelengths and not these specific colors. When you focus clearly on an object, light strikes a region called the fovea. The fovea is packed with cones and allows sharp vision. Rods outside the fovea are largely responsible for peripheral vision.Rods and cones convert light into an electric