Human Eye

Q.

What regulates the diameter of the pupil?

Q. The human eye is most sensitive to ______ colour but still most danger and alert signals are red in colour because red light scatters the ________.

1. yellow, most
2. red, least
3. blue, most
4. yellow, least

Q. Question 13
The focal length of the eye lens increases when eye muscles

(a) are relaxed and lens becomes thinner
(b) contract and lens becomes thicker
(c) are relaxed and lens becomes thicker
(d) contract and lens becomes thinner

Q.

Radius of a normal human eye ball is?

1. 2.5 mm

2. 1.15 cm

3. 2.3 cm

4. 1.25 mm

Q.

What is power of accommodation. How ciliary muscles help in accomodation?

Q. The muscles of eye of a normal person are least strained when the eye is focussed on an object

1. Far away from the eye
2. Very close to the eye
3. At about 25 cm from the eye
4. At about 1 m from the eye

Q. The eye lens becomes thin when the ciliary muscle and it becomes thicker when the ciliary muscle

1. relaxes
2. contracts
3. weakens
4. flattens

Q.

The human eye lens is crystalline and biconvex in nature?

1. True

2. False

Q.

Why do we have two eyes and not just one?

1. It gives a wide field of view

2. Helps us to see 3D

3. Enhances the ability to detect fainter object

4. All of these

Q. What are the advantages of having two eyes instead of just one ?

Q.

In human beings two eyes are positioned at the front of the head and it thus reduces the field of view in favour of what is called stereopsis.

1. False

2. True

Q. Name two animals having eyes :
(a) on the sides of the head.
(b) at the front of the head.

Q.

Where do most of the refraction of light in human eye occur?

1. cornea

2. pupil

3. iris

4. retina

Q.

Which coloured light has the largest wavelength?

1. red

2. violet

3. blue

4. green

Q. Where is the focal length of the eye located is is on the retina?

Q. The type of lens present in human eye is

1. Convex lens
2. Plano convex lens
3. Concave lens
4. Plano concave lens

Q. A young boy can adjust the power of his eye lens between 50 D and 60 D. The distance of his retina from the eye lens is (his far point is infinity)

1. 1cm
2. 2cm
3. 3cm
4. 4cm

Q. Which of the following have a wider field of view ?
(a) Animals having two eyes on the opposite sides of their head.
(b) Animals having two eyes at the front of their head.

Q. In the human eye, the acts as a pinhole of a camera and the acts as a screen.

1. retina
2. lens
3. pupil
4. iris

Q.

Name the component of eye that is responsible for the adjustment of eyelens?

Q. Among animals, the predators (like lions) have their eyes facing forward at the front of their heads, whereas the animals of prey (like rabbit) usually have eyes at the sides of their head. Why is this so ?

Q.

As we increase the distance of an object from the eye, what happens to the image distance:

Q. Persistence of vision is the time for which the sensation of an object remains in the eye even after the object is removed. It is about _____ times of one second for a normal human eye.

1. $\frac{1}{12}$
2. $\frac{1}{14}$
3. $\frac{1}{10}$
4. $\frac{1}{16}$

Q. With both eyes open, a person's field of view is about :
(a) ${90}^{\circ }$ (b) ${150}^{\circ }$ (c) ${180}^{\circ }$ (d) ${360}^{\circ }$

Q. The animal which does not have eyes that look sideways is :
(a) Horse (b) Chicken (c) Lion (d) Fish

Q. Out of animals of prey and predators, which have their eyes :
(i) at the front of their head ?
(ii) on the opposite sides of their head ?

Q. A magnifying glass or a simple microscope is used to form a magnified virtual image of a tiny object. Which of the following is the most suitable for this?

1. Glass slab
2. Glass prism
3. Concave lens
4. Convex lens

Q. What is the far point of a human eye with normal vision?

1. 25 cm
2. 100 cm
3. Infinity
4. 50 cm

Q. What is the function of optic nerve?

1. Transmits electrical signal to brain
2. Forms image
3. Keeps vitreous humour clear
4. Reduces the size of the pupil

Q. Having two eyes gives a person :
(a) deeper field of view (b) coloured field of view
(c) rear field to view (d) wider field of view