Question
Old people sometimes use bifocal glasses.
✓
Answer
(i) Few old people, suffer both myopia and hyper- meteropia.
(ii) In bifocal lens, upper part is concave lens to correct myopia and lower part is convex lens to correct hypermetropia.
(iii) The concave lens is useful for distinct vision and convex lens for near vision.
(iv) Hence, old people sometimes use bifocal glasses.
(ii) In bifocal lens, upper part is concave lens to correct myopia and lower part is convex lens to correct hypermetropia.
(iii) The concave lens is useful for distinct vision and convex lens for near vision.
(iv) Hence, old people sometimes use bifocal glasses.
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