Concave lens is used to correct a hypermetropia.

Important Questions on Human Eye and the Colorful World

EASY

10th CBSE

IMPORTANT

Eduwiser's CBSE PHYSICS FOR CLASS X>Chapter 5 - Human Eye and the Colorful World>EXERCISE>Q 6

Presbyopia is a special case of myopia that develops with old age.

EASY

10th CBSE

IMPORTANT

Eduwiser's CBSE PHYSICS FOR CLASS X>Chapter 5 - Human Eye and the Colorful World>EXERCISE>Q 7

Cataract is the defect of vision in which the eye loses its power of accommodation due to old age.

EASY

10th CBSE

IMPORTANT

Eduwiser's CBSE PHYSICS FOR CLASS X>Chapter 5 - Human Eye and the Colorful World>EXERCISE>Q 1

Hypermetropia and myopia are the most common defects of vision affecting humans. Both these defects can be corrected and perfect vision can be restored with the use of suitable lenses of appropriate focal lengths. Hypermetropia can be corrected by using convex lenses while myopia can be corrected by using concave lenses. The power of prescribed lens for both these defects depends on the focal length of the respective corrective lens. The power, $P$ of the lens is given by
$P=\frac{1}{f (\mathrm{in} \mathrm{metres})} \mathrm{dioptres}$
Now, consider a situation in which the near point of a defective eye is at a distance of $1.0 \mathrm{m}$. Assuming the near point of a normal eye to be $25 \mathrm{cm}$, answer the following question:
What type of lens should be used to correct the vision?

EASY

10th CBSE

IMPORTANT

Eduwiser's CBSE PHYSICS FOR CLASS X>Chapter 5 - Human Eye and the Colorful World>EXERCISE>Q 2

Hypermetropia and myopia are the most common defects of vision affecting humans. Both these defects can be corrected and perfect vision can be restored with the use of suitable lenses of appropriate focal lengths. Hypermetropia can be corrected by using convex lenses while myopia can be corrected by using concave lenses. The power of prescribed lens for both these defects depends on the focal length of the respective corrective lens. The power, $P$ of the lens is given by
$P=\frac{1}{f(in \mathrm{metres})} \mathrm{dioptres}$
Now, consider a situation in which the near point of a defective eye is at a distance of $1.0 \mathrm{m}$. Assuming the near point of a normal eye to be $25 \mathrm{cm}$, answer the following question: What should be the power of the corrective lens?

HARD

10th CBSE

IMPORTANT

Eduwiser's CBSE PHYSICS FOR CLASS X>Chapter 5 - Human Eye and the Colorful World>EXERCISE>Q 3

Hypermetropia and myopia are the most common defects of vision affecting humans. Both these defects can be corrected and perfect vision can be restored with the use of suitable lenses of appropriate focal lengths. Hypermetropia can be corrected by using convex lenses while myopia can be corrected by using concave lenses. The power of prescribed lens for both these defects depends on the focal length of the respective corrective lens. The power, $P$ of the lens is given by
$P=\frac{1}{f(in \mathrm{metres})} \mathrm{dioptres}$
Now, consider a situation in which the near point of a defective eye is at a distance of $1.0 \mathrm{m}$. Assuming the near point of a normal eye to be $25 \mathrm{cm}$, answer the following question:
If one wishes to reduce the near point of this eye to $0.5 \mathrm{m}$ by using a lens, what will be its power?

EASY

10th CBSE

IMPORTANT

Eduwiser's CBSE PHYSICS FOR CLASS X>Chapter 5 - Human Eye and the Colorful World>EXERCISE>Q 1

Match the items in Column I to those in Column II

Column I	Column II
(a) Corrected by concave lens	(p) Hypermetropia
(b) Corrected by convex lens
(c) Corrected by bifocal lens
(d) Long-sightedness	(q) Myopia
(e) Short-sightedness
(f) Caused by increase in focal length of eye lens
(g) Caused by excessive curvature of eye lens	(r) Presbyopia
(h) Caused by opaque membrane over eye lens
(i) Near point of the eye recedes away	(s) Cataract
(j) Far point of the eye comes closer

 

EASY

10th CBSE

IMPORTANT

Eduwiser's CBSE PHYSICS FOR CLASS X>Chapter 5 - Human Eye and the Colorful World>EXERCISE>Q 1

In a human eye, where does the highest degree of refraction occur?

HARD

10th CBSE

IMPORTANT

Eduwiser's CBSE PHYSICS FOR CLASS X>Chapter 5 - Human Eye and the Colorful World>EXERCISE>Q 2

A person suffering from an eye defect is prescribed a corrective lens of power $-0.5 \mathrm{D}$. What is the far point of his eye when he is not wearing spectacles?