Our eyes are truly an amazing piece of ‘equipment’. Your eyes are your body’s most highly developed sensory organs. In fact, a far larger part of your brain is dedicated to your vision than those of hearing, taste, touch, or smell combined!
We tend to take our eye sight for granted…but when problems arise we can get our vision back to normal. Here’s some basic info that you need to know about your eyes, common issues and how to keep em’ healthy.
Anatomy of an eye
” At the front of each eye lies the comea, a rounded bulge that allows the light inside. The light that passes through the pupil, a transparent place in the centre of the coloured iris. behind the pupil is the lens, which is connected to the zonules (ligaments that tighten and slacken to focus). light goes through the eyes and hits the retina, the tissue at the back of the eye, which sends a message through the optic nerve to the brain, telling it what your looking at.”
Eyes at all ages
When your born, the lenses inside your eyes are generally crystal clear and flexible, and the ligaments connected to them are strong.
Did you know that the eye grows during childhood? The length of the eye (from front to back) elongates nearly one third between birth and age 5 and the volume of the eye nearly doubles! As we age the senses become less flexible and the ligaments are not as effective. Your eye shape, which is genetically determined, may mean you loose corrective lenses.
Into your 40’s you begin to loose your ability to focus up close, this is called presbyopia. This is because the lenses are getting harder and the ligaments are weakening. Even if you’ve always had perfect eyesight , you mite need reading glasses around this time.
5o’s amd beyond…The lenses continue to harden and you may need stronger corrective lenses or even bifocals (which have lenses that have two perscriptions built into them). You also at greater risk of developing an eye disease.
Common vision problems
Nearsightedness & farsightedness- These issues have to do with the way the eye brings images into focus on the back of the eyeball, where 10 layers of delicate nerve tissue makes up the retina. Images that do not focus on the retina will appear blurry. The further away images focus from the retina, the blurrier they appear.
Nearsightedness (doc’s call it myopia) affects 40% of the population. The conditon runs in families and affects men and women equally, usually appearing in childhood and stabilising in the 20’s.
Farsightedness (or hyperopia) is the opposite of nearsightedness. Children often outgrow farsightedness as they mature and the eyeball reaches adult size.
Astigmatism– Nearly two thirds of the eye’s focussing power occurs along it’s front surface or comea. The normal comea should have a semi-spherical contour, similar to a soup spoon. With astigmatism, the central comea is not symetrical or uniform.
Astigmatism often combined with nearsightedness or farsightedness, occurs when the comea has a non-round curvature-more like a teaspoon. Because of that, the eye lacks a single point of focus. people with astigmatism may have a random, inconsistent vision pattern, where some objects appear clear and others blurry.
Astigmatism is usually present form birth but is typically not recognised until later in life. most astigmatism is fully correctable. It neither improves nor worsens over time.
Colour blindness- is most commonly a disorder of the retina’s light-sensitive photoreceptor cells, which respond to different coloured light rays. We have two kinds of photoreceptors- cones and rods- each produces a pigment that respond to specific colours of light. Colour vision is affected if those pigments are absent, defective or or if they respond to the wrong wavelengths. Colour perception problems occur more often in men, afflicting 24% of the male population. It is extreemly rare for someone to be totally colourblind, able to see only shades of gray.
Common eye diseases
cataracts- These form when the lenses of the eyes become cloudy. Your eye become like a window that is frosted of yellowed. Around half of Australians aged between over 65 to 74 have cataracts. The most common type if cataract is related to aging. In age related cataract, the centre of the lens gradually hardens and becomes cloudy occuring gradually over a period of years. If you begin to notice your vision blurring , visit your eye docter for an exam, cataratcs are a common cause of vision loss, but they are treatable.
Glaucoma- Glaucomia damages the optic nerve fibres, causing blind spots to develop. If the entire nerve is destroyed, blindness results. This disease affects thousands of australians and is our leading cause of blindness. Early treatment can often prevent loss of sight. Regular eye examinations by your doctor are the best way to detect glaucoma.