Sight

The sense of sight is one of the five human senses. Humans depend on it for survival and to interact with the environment. The interesting thing is that most people who have lost their sense of sight will develop acuity in the other senses such as hearing and smell. The sense of sight is mainly through the eyes.

Anatomy of the Eyes

The eye is viewed as the most complex organ in the body. It is very small yet contains very many working parts to make vision a reality. Some scientists consider it as an extension to the brain.

Sight or vision occurs when light waves are converted into nerve impulses. The nerve impulses are then transmitted to the brain which process the information and creates an image.

There are three basic layers of the eye which perform different functions: the choroids, the sclera and the retina.

The Sclera

This supports the eye and forms the outermost layer of the eye. It is the white part of the eye. External muscles of the eye are inserted into the sclera. At the front of the eye, the external muscles are transparent and form the cornea.

When light waves pass through the cornea, they are refracted and the image is focused on the retina with the aid of the lens. Right behind the cornea is the pupil.

The Choroids

This is the highly vascularized part of the eye and is its middle layer. The choroids are pigmented to absorb light that will eventually reach the retina. The anterior section of the choroids connects to the ciliary body. The contraction of the ciliary body regulates the shape of the crystalline lens.

The lens in the choroids is a true lens and its function is to focus images on the retina.

The Retina

The retina is composed of nerve fibers and photoreceptors and is the innermost layer of the eye.

When light waves pass through the cornea and the pupil, they are focused by the lens into the retina. In the retina the light will pass through two types of cells, Rods and Cones.

These cells then send the information to the brain by way of the optic nerve. The image will be upside down and the work of the brain is to turn the image right side up and then inform you on what you are looking at.

Conditions that can affect Sight

Many problems can cause the sense of sight to deteriorate. Most can be picked up early through routine eye test and treated before they result is vision loss. Some of the most common include:

Age related macular degeneration - Is a leading cause of eye loss and involves the degeneration of the macular at the center of the retina,
Diabetic retinopathy - Caused when diabetes causes blood vessels in the retina to leak or become blocked,
Glaucoma - This is an abnormal increase of pressure in the eyeball that damages the optic nerve, progressively destroying peripheral vision, and
Cataracts - A major cause of vision impairment in the elderly. It is the gradual clouding of the lens that leads to sight becoming blurred.

It is very important to protect sight as most communication with the outside world starts after one sees something. Miracles for Men recommend scheduling regular visits to your eye doctor to ensure perfect vision at all times.

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