The least distance of distinct vision for a normal human eye is about
- A. 5 cm
- B. 25 cm
- C. 100 cm
- D. infinity
Explanation
About 25 cm is the closest an object can be brought while remaining in sharp focus without strain, and it is the reference distance used in the magnifying power formula for a lens. The near point recedes with age as the eye lens stiffens, which is why reading glasses are often needed after forty. The far point of a normal eye is at infinity.
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