Good vision is a key factor for living a healthy, happy life. The earlier we start looking after the health of our eyes, the better our chance of maintaining good vision throughout our lives. Vision problems can occur at any age, which is why regular eye examinations with an optometrist are important. Good vision isn’t just about seeing well, it’s about living well. For frequently asked questions about vision and eye health, click here.
Why good vision is so important
Our world is visible to us because we have the fortune of eyesight, rendering our eyes perhaps the most precious gift we have.
Human beings have five senses: the eyes to see, the tongue to taste, the nose to smell, the ears to hear and the skin to touch. The eye is the organ which allows us to learn more about the surrounding world than any of the other senses as up to 80 per cent of all impressions are through our sight.
Our vision is also one of the most complex systems in our bodies, and yet most of us don’t give this amazing ability a second thought – until something goes wrong.
How the eye works
The inner workings of the human eye are complex, and at the same time, fascinating.
Our eyes work in a similar way to a camera. When you take a picture, the lens in front of the camera allows light through and focuses that light on the film. When the light hits the film, a picture is taken.
The eye works in much the same way. In a healthy eye, the lens is clear and allows light to pass through. Light is focused by the cornea and lens onto a thin layer of tissue called the retina. The retina works like the film in a camera. When light hits the retina, tiny cells collect the light signals and convert them into electrical signals, which are then sent through the optic nerve and to the brain, which are processed into the images we see.
The anatomy of the eye
Click on the below list for an explanation of each part of the eye, and see where it is located in the illustration.
The outer coat of the eyeball that forms the visible white of the eye and surrounds the optic nerve at the back of the eyeball. The sclera acts as the tough outer layer to protect the eye from injury.
The thin, dark-brown vascular layer between the sclera and the retina. The choroid supplies blood to the retina and nerves to other structures in the eye.
The innermost layer at the back of the eyeball that contains cells sensitive to light. It receives images formed by the lens and converts them into signals that reach the brain via the optic nerve, to enable a visual image to be formed.
Connects the eye to the brain, via sensory fibres that conduct the impulses formed by the retina.
A special area in the centre of the retina, which is the area of keenest vision, allowing us to see objects in great detail.
The raised disc on the retina at the point of entry of the optic nerve, lacking visual receptors, thereby creating a blind spot.
The transparent, biconvex body in the eye. Along with the cornea, the lens helps to refract light to focus on the retina.
The circular muscle that surrounds the lens and contracts or relaxes to enable the lens to change shape for focusing objects up close or far away.
The coloured part of the eye surrounding the pupil. The iris acts as a diaphragm to widen or narrow the opening called the pupil, thereby controlling the amount of light that enters the eye.
The black hole at the centre of the eye that allows light through.
The clear window forming the front of the eye. It lets light into the eye, assisting with focusing to enable clear vision.
Your age, your vision
Just like the rest of our bodies, our eyes also experience changes as we age.
For maximum eye health, we should be aware of which vision changes to expect, as well as be able to notice if something more serious is going on. For more information, click through to one of the sections below.