How Eyes Work?
Eyes work in a similar way to a camera so in order to see clearly objects need to brought to a focus point on the back surface of the eye which is the retina, just like an object is focussed onto film. The light enters through the pupil and passes through the lens which is clear and flexible and acts just like a camera lens.
As light is passed through the lens it changes shape and makes delicate adjustments so the light rays come into focus as a clear picture on the back of the eye and just like a camera the image is backwards and upside down.
The rays of light are captured by the Retina (it acts in a similar way to film) which contains light sensitive cells that convert light rays into electrical impulses that are sent to the brain via the Optic nerve.
The brain develops these impulses and turns the image the right way up, this is the process of seeing. If you have normal vision the images are focussed exactly onto the Retina giving clear vision at all distances.
Why do we wear glasses?
We become accustomed to eyesight that has degenerated over time and it's only after an eye test that we realize how much more we can see with better eyesight.
Just like a camera, if one of the components is not working correctly the result is a poor image or in the case of the eye, blurred vision.
The usual cause is that the eye is slightly out of shape, more like a rugby ball than a football and this causes the the rays of light to focus incorrectly on the Retina. This causes eye conditions such as long sight, short sight or Astigmatism.
These reasons and the changes in our eyes as we age are the most common reasons why people wear glasses or contact lenses.
An eye test will determine just what the problems are and from that investigation an Optician is able to make a lens that is perfectly suited to each eye.
About The Author
The author, John Buckle was lucky enough to discover he had Glaucoma before serious damage had occurred and now has an interes! t in eye care Better Eyesight
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