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Why is a normal eye not able to see clea...

Why is a normal eye not able to see clearly the objects placed closer than 25 cm?

Text Solution

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For seeing nearby objects, the ciliary muscles contract to make the eye lens thicker near the middle, so as to reduce the focal length of the eye lens.
But ciliary muscles cannot be contracted beyond a certain limit and hence we cannot see clearly the objects closer than 25 cm from the eye.
In other words, a normal eye is not able to see clearly the objects placed closer than 25 cm because all its power of accommodation has already been exhausted.
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