An old person is suffering from an eye defect caused by weakening of ciliary muscles and diminishing flexibility of the eye lens. If the defect of vision is ‘a’ which can be corrected by lens ‘b’, then ‘a’ and ‘b’ respectively are :
options
Hypermetropia and convex lens
Presbyopia and bifocal lens
Myopia and concave lens
Myopia and bifocal lens

Question

An old person is suffering from an eye defect caused by weakening of ciliary muscles and diminishing flexibility of the eye lens. If the defect of vision is ‘a’ which can be corrected by lens ‘b’, then ‘a’ and ‘b’ respectively are :
options
Hypermetropia and convex lens
Presbyopia and bifocal lens
Myopia and concave lens
Myopia and bifocal lens

KnowledgeBoat · Accepted Answer

Presbyopia and bifocal lens Reason — As people age the ciliary muscles weaken and the eye lens loses flexibility, so the eye cannot focus on near objects — a condition called presbyopia. This is typically corrected using bifocal lenses, which provide a separate near-vision segment (convex part) for reading and a distance-vision segment, allowing the person to see both near and far objects comfortably. Hence the correct pair is presbyopia and bifocal lens.

Science

Human Eye

Answer

Related Questions

Which of the following groups do not constitute a food chain ?
(a) Wolf, rabbit, grass, lion
(b) Plankton, man, grasshopper, fish
(c) Hawk, grass, snake, grasshopper, frog
(d) Grass, snake, wolf, tiger
options
(a) and (d)
(a) and (c)
(b) and (c)
(b) and (d)

The percentage of solar energy which is not converted into food energy by the leaves of green plants in a terrestrial ecosystem is about :
options
1%
10%
90%
99%