Jason

Investigate the two types of sight defect; long sightedness and short sightedness.

Find the following information:

1. What causes the defect?
Long sightedness: The causes are not exactly known but some cases are beleived to be caused because it is hereditary.
Short Sightedness: Light focuses infront instead of behind the eyes retina and a blurred image is created. Can be caused by certain drugs or if it runs in your family.

2. The symptoms displayed.
Long sightedness: You are unable to focus, particularly on objects upclose and are seeing objects as blurry.
Short Sightedness: You are unable to focus upon distant objects, they appear blurred. Nearby objects remain clear and unchanged.

3. Propose what sort of lens may be used to correct each vision.
Long sightedness: Glasses & contact lenses are commonly used.
Short Sightedness: Glasses & contact lenses are commonly used.