Why does eyesight deteriorate with age

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[edit] Introductory Note

Many of us think that as we grow older our eyesight is destined to deteriorate. We talk about "tired" or "old" eyes as if we are fated to have the gift of vision taken from us simply because we have aged. For example, in what might be the earliest reference to cataracts in the Bible (Genesis, Chapter 27, Verse 1) we learn that, "And it came to pass, that Isaac was old, and his eyes were dim..." The truth is that, with today's treatment options, there is no intrinsic reason for our vision to worsen with time. In theory, we should be able to retain undiminished our capability to accept, process and experience visual sensory input.But there is an element of truth to the notion that age-related processes can affect our eyesight. The good news is that identifying and treating these processes can often result in the preservation or restoration of excellent vision for an entire lifetime.

[edit] Reason

During the first 12 years of our lives, up to 80% of our learning is visually based. Many children struggle at school, simply because of eye-related problems. We have to remember that what a child sees is normal for them and may not realise that others can see clearer. There are a few tell-tale signs you can look out for: Does your child sit close to the TVS; do they rub their eyes repeatedly; do they complain of headaches or blurred vision?Throughout our lives our bodies are continually growing and replacing cells. The same applies to our eyes. Generally our eyesight and prescription details remain relatively stable, with only subtle changes over time. Opticians recommend an eye test every two years for any adult between the ages of 16-60.The natural aging process means that the eyes do not function the same throughout all our lives. Around the age of 45, everybodys eyesight starts to alter. You find some close-up tasks harder to focus on and have to push things further away. You may need more light to be able to read and you may even find yourself getting headaches when reading or using the VDU. This is a perfectly normal process called Presbyopia and is caused by the natural lens in your eye not being able to flex as it once did, causing near vision to seem blurred.

The aging process in the eyes does bring with it certain changes. The optical structures in the eyes become more opaque, leaving us needing more light to see clearly, especially if there are any cataract changes happening to the natural lens in the eye. The pupils of the eyes become smaller often making it more difficult to see especially at night. Floaters increase with age causing blobs to swim through the field of view. Often people find they eyes seem to be dryer and more uncomfortable either on waking or last thing at night.Most people will have very few problems with their eyes. By using the correct spectacles, having regular eye tests at your local optician and by being aware of any changes happening to your eyes and eyesight, you can help your optician, help you look after your eyes. Generally, if there are any problems the sooner they are dealt with, the better. If some cases, if a problem is left undetected it may mean the child has a defect, which cannot then be corrected. Qualified opticians do provide the appropriate eye tests, eye care and eye care products.

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• Take a moment to locate an object around you. Do you know how you are able to see it? Would you believe that what you are actually seeing are beams of light bouncing off of the object and into your eyes? It is hard to believe, but it is true. The light rays enter the eye through the cornea, which is a thick, transparent protective layer on the surface of your eye. Then the light rays pass through the pupil (the dark circle in the center of your eye) and into the lens.

• The retina, which is the size of your thumbnail, is filled with approximately 150 million light-sensitive cells called rods and cones. Rods identify shapes and work best in dim light. Cones on the other hand, identify color and work best in bright light. Both of these types of cells then send the information to the brain by way of the optic nerve. The amazing thing is, when they send the image to the brain, the image is upside down! It is the brain's job to turn the image rightside up and then tell you what you are looking at. The brain does this in a specific place called the visual cortex.

• Because the eye is such an important and complex part of our body, we have many features which protect the eye. The eyebrows are the strips of hair above your eyes which prevent sweat from running into them. Eyelashes help keep the eye clean by collecting small dirt and dust particles floating through the air. The eyelashes also protect the eye from the sun's and other light's glare. The eyelids sweep dirt from the surface of the eye. The eyelid also protects the eye from injury. Tears are sterile drops of clean water which constantly bathe the front of the eye,keeping it clean and moist.

• Not all people have perfect vision. People who can see things up close, but not far away are considered to be nearsighted. This happens when the light entering the eye focuses on a point in front of the retina. On the other hand, people who can see far away objects but not those that are up close are farsighted. Farsightedness occurs when the light that enters the eye focuses on a point behind the retina. Whether a person is nearsighted or farsighted, glasses or contacts help that person to see things much more clearly!

[edit] References

1. eyesight

2. How Eyesight Changes With Age

3. Your sense of sight

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