Tag: human eye and its working

Questions Related to human eye and its working

Transparent front part of eye is:

  1. pupil

  2. cornea

  3. iris

  4. retina


Correct Option: B
Explanation:

Light enters the eye through a curved front surface known as cornea. It is transparent in nature.

The part of human eye which is sensitive to red, blue and green light is:

  1. retina

  2. lens

  3. cornea

  4. iris


Correct Option: A
Explanation:

Retina is the screen of eye. Photo-receptors like rodes and cones are present on retina. So it is sensitive to different colours.

The space between cornea and eye lens is filled with a liquid known as:

  1. aqueous humour

  2. vitreous humour

  3. corneal fluid

  4. none of these


Correct Option: A
Explanation:

The space between cornea and eye lens is filled with a viscous liquid known as  aqueous humour.

When light enters the eyes, most of the refraction occurs at the :

  1. lens

  2. outer surface of cornea

  3. iris

  4. pupil


Correct Option: B
Explanation:

When light enters the eyes, most of the refraction occurs at the outer surface of cornea. It is the whitish part of eye.

Match the column:


a. optic nerve i. coloured part of the eye
b. ciliary muscle ii. refracts light and focuses a real image on the back of eye
c. lens iii. it can increase or decrease the thickness of lens
d.iris iv. carries information to the brain about light that strikes the retina

  1. a-i,b-iii,c-iv,d-ii

  2. a-ii,b-i,c-iv,d-iii

  3. a-iii,b-iv,c-i,d-ii

  4. a-iv,b-iii,c-ii,d-i


Correct Option: D
Explanation:

Optic nerve carries information from retina to brain.

Iris is the coloured part of eye. It changes in size to vary the amount of light entering through the pupil.
The lens of the eye forms a real,inverted image of the object on the inner coat of the eye. The screen of eye is called the retina.Eye lens is a convex lens.
Ciliary muscle is a muscle surrounding the eye that can increase or decrease the curvature of lens.

Function of optic nerve in human eye:

  1. Image is modified by the optic nerves

  2. Electric signals are generated on the retina are carried by the optic nerve to the brain

  3. Image brightness is reduced by the optic nerve

  4. All the above


Correct Option: B
Explanation:

The light sensitive cells of the retina gets activated with the incidence of light and generates electric signals. The electric signals are sent to the brain by the optic nerve and the brain interprets the electric signals in such a way that we see an image which is erect and of the same size as the object.

When you enter a dim lighted room from sunlight at noon time.What is the change in size of pupil?

  1. In the sunlight pupil contracts and after entering a dim lighted room the size of pupil increases.

  2. In dim light size of pupil decreases and in sunlight the pupil size increases

  3. Both  A and B can  occur.It depends on the size of eye

  4. No change in size of pupil


Correct Option: A
Explanation:

In sunlight the size of pupil decreases but in dim light the pupil gets enlarged and thus lets more light into the eye.

Image forming light sensitive screen of the eye is known as __________ and it contains __________.

  1. iris, blind spot

  2. cornea, blind spot

  3. retina, photoreceptors

  4. cornea, photoreceptors


Correct Option: C
Explanation:

The lens of the eye forms a real, inverted image of the object on the inner coat of the eye. The screen of eye is called the retina. It is a delicate membrane having enormous number of light sensitive cells or photo-receptors, i.e rod and cone cells. 

What is the function of aqueous humour?

  1. Helps in transmitting impulses to the brain

  2. Protect the eyeball from collapsing

  3. Keeps the cornea moist and give definite shape to the eyeball

  4. All


Correct Option: C
Explanation:

Aqueous humour is present between cornea and eye lens. It keeps the cornea moist and maintains the shape of eye ball.

Which of the following is true for vitreous humour?
a. It is a clear gel like fluid.
b. It is present between the lens and the cornea.
c. It maintains the shape of the retina.
d. It provides nutrition to the eye.

  1. a and b

  2. c and d

  3. a and c

  4. all of the above


Correct Option: C
Explanation:

Vitreous humour is a clear gelatinous gel like fluid that fills the space between the lens and the retina. It helps in maintaining the shape of the retina by holding it in its place.