HUMAN EYE
Class 10 - Science
Section A
1. The image formed by the retina of the human eye is: [1]
a) Real and erect b) Virtual and inverted
c) Virtual and erect d) Real and inverted
2. The value of least distance of distinct vision for a normal human eye is ________. [1]
a) 25 cm b) 70 cm
c) 35 cm d) 45 cm
3. The change in the focal length of an eye lens in human beings is caused by the action of [1]
a) ciliary muscles b) optic nerves
c) retina d) cornea
4. Statement 1: A normal human eye can clearly see all the objects at a distance less than or greater than 25 m. [1]
Statement 2: The human eye has the capacity to suitably adjust the focal length of its lens to a certain extent.
a) Statement 1 is true but statement 2 is false. b) Statement 1 is true but statement 2 is false.
c) Both statements 1 and 2 are true and d) Both statements 1 and 2 are true but
statement 2 is the correct explanation of statement 2 is not the correct explanation of
statement 1. statement 1.
5. The lens of the eye can become thicker and thinner. Why is this flexibility useful? [1]
a) The lens is not likely to break. b) The lens allows the eye to focus on far
objects as well as near objects.
c) The eye can move up, down, left and right. d) The lens can allow varying amounts of light
to enter the eye.
6. Observe the given diagram carefully. What could be the causes of this defect? [1]
i. The focal length of the eye lens is too long.
ii. The eyeball becomes too small.
iii. The focal length of the eye lens is too small.
iv. The eyeball becomes too long.
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a) Only (i) and (iv) b) Only (i) and (ii)
c) Only (iii) and (iv) d) Only (ii) and (iii)
7. A person with a myopic eye cannot see objects beyond 1.4 m distinctly. The type of the corrective lens used to [1]
restore proper vision should be
a) A convex lens of focal length 1.4 m and b) A convex lens of focal length -1.4 m and
power +0.71 D power -0.71 D
c) A concave lens of focal length -1.4 m and d) A concave lens of focal length -1.4 m and
power -0.71 D power +0.71 D
8. The defect of vision in which a person is able to see nearby objects clearly, but not far objects is called: [1]
a) Long-sightedness or Hypermetropia b) Short-sightedness or myopia
c) Astigmatism d) Cataract
9. An optician while testing the eyes find the vision of a patient to be 6
9
. By this he means that [1]
a) The person can read letters from 9 m which b) The person can read letters from 6 m which
the normal eye can read from 6 m. the normal eye can read from 9 m
c) The person can read the letters of 9 inches d) The person can read the letters of 6 inches
from 6 m from a distance 9 m
10. An old person is unable to see clearly nearby objects as well as distant object. To correct the vision, what kind of [1]
lens will he require?
a) Bifocal lens whose upper portion is concave b) Concave lens
lens and lower portion is convex lens
c) Bifocal lens whose upper portion is convex d) Convex lens
lens and lower portion is concave lens
11. Assertion (A): The curvature of the eye lens can be modified to some extent by the ciliary muscles. [1]
Reason (R): The ciliary muscles are used to modify the curvature of lens.
a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
12. Assertion (A): The farthest point up to which the eye can see objects clearly is called the far point of the eye. [1]
Reason (R): The nearest point up to which the eye can see objects clearly is called the least point of the eye.
a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
13. Assertion (A): It is possible to correct the refractive defects with contact lenses or through surgical [1]
interventions.
Reason (R): The eye lens is composed of fibrous jelly-like material.
a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.
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c) A is true but R is false. d) A is false but R is true.
14. Assertion (A): A person suffering from myopia cannot see the distant objects clearly. [1]
Reason (R): A converging lens is used for the correction of myopic eye as it can form real as well as virtual
images of the objects placed in front of it.
a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
15. Assertion (A): Sometimes, the eye may gradually lose its power of accommodation. [1]
Reason (R): The crystalline lens of people at old age becomes milky and cloudy.
a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
16. Define power of accommodation? [1]
17. Which part of the human eye conveys the electrical signals generated by the light sensitive cells of the retina to [1]
the brain?
18. What happens to the lens and the ciliary muscles when you are looking at nearby objects? [1]
19. Variable focal length of the eye lens is responsible for which property of eye? [1]
20. What is the function of the liquid filled in the space between the eye lens and retina? [1]
21. Where do we see the following lenses in a bifocal spectacle? [1]
i. concave lens
ii. convex lens
22. A person is advised to wear spectacles with convex lenses. What types of defect of vision is he suffering from? [1]
23. Observe the following diagram and answer the questions following it: [1]
i. Identify the defect of vision shown.
ii. List its two causes.
iii. Name the type of lens used for the correction of this defect.
24. Where is the image formed in an eye suffering from near-sightedness? [1]
25. Where is the image formed in an eye suffering from long sightedness? [1]
Section B
26. What is colour blindness ? How can it be cured ? [2]
27. We are able to see everything with one eye, then why do we have two eyes ? [2]
28. How do we see objects erect when the eye forms a real, inverted image of them on its retina? [2]
29. Write the structure of eye lens and state the role of ciliary muscles in the human eye. [2]
30. Calculate maximum power of accommodation of a person having normal vision. [2]
31. What type of lens we wear if we are suffering from myopia ? [2]
32. A myopic person can see things clearly only when they lie between 10 cm and 100 cm from the eye. Which lens [2]
will enable him to see the Moon clearly?
33. Ahmed cannot distinguish between red and green colour. Why? Does he have normal vision? [2]
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34. The near point of a hypermetropic person is 50 cm. What should be the focal length and power of the lens used [2]
by him if he wants to read a newspaper placed 20 cm. away ?
35. When we increase the distance of an object from the eye, what happens to the image distance in the eye? [2]
36. Why does a person suffering from hypermetropia prefer to remove his spectacles while looking at distant [2]
objects? Explain.
37. In a certain murder investigation, it was important to discover whether the victim was long-sighted or short- [2]
sighted. How could a detective decide by examining his spectacles?
38. i. Ravi kept a book at a distance of 10 cm from the eyes of his friend Hari. Hari is not able to read anything [2]
written on the book. Explain, why?
ii. A lens of focal length 5 cm is being used by a student in the laboratory what magnification is the student
getting?
39. What would be your suggestion to your grandfather who is undergoing the eye defects both hypermetropia and [2]
myopia?
40. A person may suffer from both myopia and hypermetropia defects. [2]
i. What is this condition called?
ii. When does it happen?
iii. Name the type of lens often required by the persons suffering from this defect. Draw labelled diagram of
such lenses.
Section C
41. When one enters a less lighted room from a place of intense light, he is not able to see anything for sometime, [3]
but after sometime the things become somewhat visible. Explain how this happens?
42. i. State two main causes of a person developing near-sightedness. With the help of a ray diagram, suggest how [3]
he can be helped to overcome his disability?
ii. The far point of myopic person is 100 cm in front of the eye. Calculate the focal length and power of a lens
required to enable him to see distant objects clearly.
43. What are the common defects of vision that can be corrected by the use of suitable eyeglasses or spectacles? [3]
Section D
44. Explain the structure and functioning of the human eye. How are we able to see nearby as well as distant [5]
objects?
45. With the help of well labeled diagram, explain the construction and working of human eye. [5]
46. Make a diagram to show how hypermetropia is corrected. The near point of a hypermetropic eye is 1 m. What is [5]
the power of the lens required to correct this defect? Assume that the near point of the normal eye is 25 cm.
47. A person is unable to read a book properly. From which defect is he suffering? How to correct this defect? [5]
48. The near point of a hypermetropic eye is 1 m. What is the power of the lens required to correct this defect? [5]
Assume that the near point of the normal eye is 25 cm.
49. Differentiate between myopia and hypermetropia. [5]
50. a. What is myopia? State the two causes of myopia. With the help of labelled ray diagrams show [5]
i. the eye defect myopia
ii. correction of myopia using a lens.
b. Why is the normal eye unable to focus on an object placed within 10 cm from the eye?
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