Other Eyes Defects

Q.

A person needs a lens of power $+3D$ for correcting his near vision and$–3D$ for correcting his distant vision. Calculate the focal lengths of the lenses required to correct these defects.

Q.

A man can see only between 75 cm and 200 cm. The power of lens to correct

the near point will be

1. + 8/3 D
2. + 3 D

3. - 3 D

4. - 8/3 D

Q. A person's near point is 50 cm and his far point is 3 m. Power of the lenses he requires for (i) reading and
(ii) for seeing distant stars are

1. – 2 D and 0.33 D
2. 2 D and – 0.33 D
3. – 2 D and 3 D
4. 2 D and – 3 D

Q.

If there had been one eye of the man, then

1. Image of the object would have been inverted

2. Visible region would have decreased

3. Image would have not been seen three dimensional

4. (b) and (c) both

Q.

Astigmatism (for a human eye) can be removed by using

[CPMT 1972; MP PET/PMT 1988; CBSE PMT 1990]

1. Concave lens

2. Convex lens

3. Cylindrical lens

4. Prismatic lens