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प्रश्न
Name the defect of vision in a person:
whose far point is less than infinity
उत्तर
Myopia is the defect of vision in a person whose far point is located closer than infinity.
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संबंधित प्रश्न
Name the defect of vision in which the eye-lens loses its power of accommodation due to old age.
The defect of vision which cannot be corrected by using spectacles is:
(a) myopia
(b) presbyopia
(c) cataract
(d) hypermetropia
A short-sighted person has a near point of 15 cm and a far point of 40 cm.
(a) Can he see clearly an object at a distance of:
(i) 5 cm?
(ii) 25 cm?
(iii) 50 cm?
(b) To see clearly an object at infinity, what kind of spectacle lenses does he need?
What is meant by optical illusion? Give one example.
Give Reason:
Why do we see clearly in the central region of the retina?
Explain the Term: Cataract
What type of lens is used to correct Astigmatism?
A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power:
Assertion: Concave mirrors are used as reflectors in torches, vehicle head lights and in search lights.
Reason: When an object is placed beyond the center of curvature of a concave mirror, the image formed is real and inverted.
When do we consider a person to be myopic or hypermetropic? Explain using diagrams how the defects associated with myopic and hypermetropic eye can be corrected?
