A person with hypermetropia (farsightedness) is prescribed a lens to correct their vision. Which type of lens and action is used in their spectacles?
Convex lens; converging action
In hypermetropia a person sees distant objects clearly but cannot see nearby objects clearly, because the near point moves farther away. Light from a nearby object is focused behind the retina, as the eyeball is too short or the focal length of the eye lens is too long.
A convex lens converges the rays before they enter the eye, so the image of a nearby object forms on the retina. So spectacles with a convex lens of suitable power, which has a converging action, correct this defect.
A concave lens is always diverging and is used to correct myopia (nearsightedness). Pairing a concave lens with converging action, or a convex lens with diverging action, is not possible, because the shape of a lens fixes its action.
Hence, Convex lens; converging action.
Similar Questions
An object is placed 10 cm from a diverging lens with a focal length of 15 cm. What is the position of the image formed?
A ray of light passes through the center of curvature of a concave mirror after reflection. Which path will it follow and why?
Identify the statement(s) that accurately describe situations involving refraction.
(i) The apparent depth of a swimming pool is less than its actual depth due to refraction.
(ii) We are able to see our image in a plane mirror due to refraction.
(iii) A pencil partially dipped in water appears bent at the water surface due to refraction.
(iv) Refraction makes a white wall appear colored at night.
Which of the following statements about image formation by spherical mirrors is NOT correct?
Which feature best describes the orientation and size of the image produced by a convex mirror for any object position?
If an image formed by a spherical mirror is real and inverted, which of the following correctly describes the sign of the image distance according to the sign convention?
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In the context of spherical mirrors, what is the relationship between the principal axis and the normal at the pole?
Which property of convex mirrors makes them suitable for use in shopping malls for security purposes?
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Important Questions from Optics
Who was the first one to use a glass prism to obtain the spectrum of sunlight?
Twinkling of stars is due to:
In which a convex mirror is used?
A. Rear View mirrors in vehicles
B. Glass windows
C. Makeup Mirror
D. Kaleidoscope
An object is placed 10 cm in front of a lens. The image formed is real, inverted and of same size as the object. What is the focal length and nature of the lens?
The power of a lens is -2.5 D. The type of lens and its focal length are respectively:
