Structure of Eye

Q. What is the approximate shape and diameter of the eyeball of a human eye?

1. Spherical, 2.3cm
2. Oval, 2.5cm
3. Round, 2.35cm
4. Elliptical, 3cm

Q. The minimum power of eye lens is 40D .if the far point of normal eye is infinity , find the size of the eyeball

Q. (a) Draw a simple diagram of the human eye and label clearly the cornea, iris, pupil, ciliary muscles, eye-lens, retina, optic nerve and blind spot.
(b) Describe the working of the human eye with the help of the above diagram.
(c) How does the eye adjust itself to deal with light of varying intensity ?

Q.

The part of the human eye, where rod cells and cone cells are located in the

1. retina

2. cornea

3. choroid

4. sclera

Q.

Which of the following statements is correct regarding rods and cones in the human eye?

1. Cones are sensitive to dim light.

2. Cones are sensitive to bright light.

3. Rods are sensitive to bright light.

4. Rods can sense colour.

Q.

State whether the following statements are true or false.

2. Cones are the receptor cells in the retina of eye, which are sensitive to dim light.

1. True
2. False

Q.

The eye lens is held in position by

1. rods and cones

2. iris and pupil

3. ciliary muscles

4. none of these

Q. Give the scientific names of the following parts of the eye :
(a) carries signals from an eye to the brain.
(b) muscles which change the shape of the eye-lens.
(c) a hole in the middle of the iris.
(d) a clear window at the front of the eye.
(e) changes shape to focus a picture on the retina.

Q.

Label the eye parts correctly.

i) Aqueous humour ii) vitreous humour iii) cornea iv) iris v) pupil

1. A-i; B-ii, C- iii, D-iv, E- v

2. A-i;B-v, C- iii, D-ii, E- iv

3. A-iii;B-ii, C- i, D-iv, E- v

4. A-i;B-v, C- iii, D-iv, E- ii

Q.

The most comfortable distance at which one can read with a normal eye is about ________ cm.

Q.

The amount of light reaching the retina of the eye is controlled by?

Q. A person cannot see objects beyond 5 m clearly. What should be the power of the corrective lens?

1. -5 D
2. -0.2 D
3. +3.8 D
4. +0.2 D

Q.

Choose the correct option.

i) Aqueous humour ii) vitreous humour iii) cornea iv) iris v) pupil

1. A-i;B-v, C- iii, D-iv, E- ii

2. A-i; B-ii, C- iii, D-iv, E- v

3. A-i;B-v, C- iii, D-ii, E- iv

4. A-iii;B-ii, C- i, D-iv, E- v

Q.

Which of the following regulates the amount of light entering the eye?

1. Lens

2. Iris

3. Cornea

4. Retina

Q.

Focal length of relaxed eye is

1. 7.5 cm

2. 1.7 cm

3. 25 cm

4. 10 cm

Q. What change is made in the eye to enable it to focus on objects situated at different distances ? Illustrate your answer with the help of diagrams.

Q.

The eye-lens can change its focal length by changing its thickness with the help of its muscles.

Q.

The process by which the eye changes the focal length of the eye lens so as to always obtain the image at the retina is called

1. accommodation

2. dispersion

3. scattering

4. total internal reflection

Q.

Label the eye parts correctly.i) Aqueous humour ii) vitreous humour iii) cornea iv) iris v) pupil

1. A-i; B-ii, C- iii, D-iv, E- v

2. A-i;B-v, C- iii, D-ii, E- iv

3. A-iii;B-ii, C- i, D-iv, E- v

4. A-i;B-v, C- iii, D-iv, E- ii

Q. Which part of the human eye helps in changing the focal length of the eye lens?

Q. What is the least distance of distinct vision of a normal human eye?

1. 10 cm
2. 100 cm
3. 25 cm
4. 25 m

Q.

Label the eye parts correctly.

1. A-i;B-ii, C- iii, D-iv, E- v

2. A-i;B-v, C- iii, D-ii, E- iv

3. A-iii;B-ii, C- i, D-iv, E- v

4. A-i;B-v, C- iii, D-iv, E- ii

Q. Aqueous humour is a _________ and vitreous humour is a _________.

1. Viscous fluid, transparent jelly
2. Transparent jelly, viscousfluid
3. Transparent jelly, watery fluid
4. Viscous fluid, viscous fluid

Q. __________ is the dark muscular diaphragm that controls the size of the pupil.

1. Aqueous humour
2. Iris
3. Cornea
4. Ciliary muscle

Q. Which part of eye is responsible for its characteristic colour

1. Iris
2. Cornea
3. Pupil
4. Sclera

Q. Lens of an eye is a transparent spherical structure which:

1. diffracts light
2. scatters light
3. refracts light
4. reflects light

Q. Suppose the vitreous humour of the eye dries off. Then what will be its effect on our eyes?

1. The eye ball will swell up
2. The eyeball will collapse
3. A brighter image will be formed on retina
4. Cornea will become dry

Q. The distance between the eye lens and retina is about __________.

Q. Cornea is a transparent spherical structure which :

1. Scatters light
2. Reflects light
3. Refracts light
4. None of these

Q. The film of camera is compared to which part of human eye?

1. Lens
2. Retina
3. Iris
4. Choroid