Advertisements
Advertisements
प्रश्न
State reasons for Myopia. With the help of ray diagrams, show the:
- image formation by a myopic eye, and
- correction of myopia using an appropriate lens.
Advertisements
उत्तर
Myopia is a visual impairment in which a person can see all around objects clearly, but finds it difficult to comfortably focus on a single object. This eye is referred to as the myopia eye.
Myopia can be caused by:
- increase in curvature of the lens.
- increase in the length of the eye ball.
(a) A myopic eye's far point is close to that infinite distance. In front of the retina, it creates the separate object image depicted in the figure.
(b) Concave lens has an ability to diverge incoming rays, it is used to correct this defect of vision. The image is allowed to form at the retina by using a concave lens of suitable power as shown in the figure.
APPEARS IN
संबंधित प्रश्न
Name the defect of vision in a person:
whose near point is more than 25 on away.
Which defect of vision can be rectified:
by using a convex lens?
What is the other name for
myopia
What is the scientific name of
long-sightedness?
A man can read the number of a distant but clearly but he finds difficulty in reading a book.
What type of spectacle lens should he use to correct the defect?
An eye has a far point of 2 m. What type of lens in spectacles would be needed to increase the far point to infinity? Also calculate the power of lens required. Is this eye long-sighted or short-sighted?
Explain the terms ‘adaptation’ and ‘accommodation’ with reference to the eye.
Given below is a diagram depicting a defect of the human eye. Study the same and answer the question that follow:
Name the defect shown in the diagram.
Explain the Term: Presbyopia
Give Technical Term:
The type of lens used to correct myopia is
