Sat March 05, 2011 By: Srijan Sood

Compare the human eye and a camera.

Expert Reply
Sat March 05, 2011
Dear student
1. Both have bi-convex lens.
2. Both forn real, inverted and diminished image of the object.
3. The adjustment of the aperture in the diaphragm controls the amount of light entering the camera, similarly, the adjustment in the size of pupil with the help of iris, controls the amount of light entering the eye.
4. The entry of light can be cut off or allowed by a shutter in the camera, similarly, the entry of light can be either cut off or allowed by the eyelids.
1. The focal length of a camera lens is constant but the focal length of the crystalline lens can be increased or decreased with the help of ciliary muscles.
2. A permanent image is formed on the film but the image formed on retina is not permanent. It is retained for about 1/16 of a second.
3. The same film cannot be used repeatedly but the retina is used repeatedly to form different images.
4. Camera is empty from withing, i.e. it is not filled with any liquid but the human eye is filled with aqueous humour and vitreous humuor.
Hope this clarifies your doubt.
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