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A person can see only objects between 0.5 m and 2 m clearly. Which lenses (in order: distance, near) should the bifocal carry?
AConcave for both
BConvex for distance, concave for near
CConcave for distance, convex for near
DConvex for both
Answer & Solution
Correct answer: C. Concave for distance, convex for near
1. Can't see beyond 2 m → myopia → distance correction needs concave.
2. Can't see closer than 0.5 m → hypermetropia/presbyopia → near correction needs convex.
3. Bifocal: upper concave portion, lower convex portion.
_Source: NCERT Class 10 Science, Ch 10 "The Human Eye and the Colourful World", §10.2_
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