Shreyash

nvestigate the two types of sight defect- long-sightedness and short sightedness.

Find the following information:

1. what causes the defect

 Long-sightedness: long-sightedness is caused by the light rather than being focused on the retina it is focused behind the retina which causes a blurry image.

Short-sightedness: Short-sightedness is caused when light is focused in front of the retina rather than being focused on the retina this will cause blurring of an image like long-sightedness.

1. the symptoms displayed

Short-sightedness: Causes distant objects to appear blurry and unfocused, while nearby objects remain in focus. (http://hcd2.bupa.co.uk/fact_sheets/html/myopia.html#1)

 Close objects appear fuzzy or blurry, while distant objects remain in focus.

 Headaches or tired eyes. In young people with long sight, the eyes can still focus on near objects, for example when reading a book. But the muscles in the eye have to contract more to allow this. So you might find that you get headaches when you read, write or do other near work, and that your eyes feel tired.  

(http://hcd2.bupa.co.uk/fact_sheets/html/long_sightedness.html)