Human Eye

Q.

What is the range of vision of a normal human eye ?

Q.

What is the Persistence of Vision?

Q.

What type of lens (convex or concave) is present in the human eye ?

Q.

List different ways of taking care of your eyes?

Q. The impression of an image persists on the retina for how long?

1. 16 seconds
2. $\frac{1}{16}th$ of a minute
3. $\frac{1}{16}th$ of a second
4. 16 minutes

Q. Explain the function of the following parts of the human eye:-
1) Sclera
2) Cornea
3) Iris
4) Pupil
5) Crystalline lens
6) Aqueous Humor
7) Vitreous Humor
8) Ciliary Muscles
9) Retina
10) Optic Nerve

Q. The change in focal length of eye lens is caused due to:

1. iris
2. ciliary muscles
3. pupil
4. cornea

Q.

Deficiency of which vitamin causes night blindness?

1. Vitamin A

2. Vitamin D

3. Vitamin E

4. Vitamin K

Q.

A person who cannot see is called a _____?

Q.

Which of the following cells in eyes are sensitive to dim light?

1. Cones

2. Rods

3. Iris

4. Cornea

Q.

What is the horiontal field of view for a single-eyed human?

1. ${90}^0$

2. ${120}^0$

3. ${150}^0$

4. ${180}^0$

Q. Which part of the human eye is resposible for color perception?

1. Cones
2. Rods
3. Iris
4. Pupil

Q.

What should we do if something like a dust particle or an insect gets into our eye?

Q. Which of the following alternatives regarding a blind spot is/are correct?

1. Has no sensory cells
2. No vision possible at that spot
3. Present in the retina
4. Present in the lens

Q.

Complete the following sentences by choosing the correct alternative out of those given within brackets.

The cones are sensitive to _______ light. ( dim/ bright).

Q. At the junction of and optic nerve, no vision is possible due to the absence of sensory cells. This is called

1. iris
2. retina
3. blind spot
4. pupil

Q.

If your eye glasses have focal length 60 cm, what is your near point? [2 MARKS]

Q.

Question 18

What kind of lens is there in our eyes? Where does it form the image of an object?

Q.

What is the space between the lens and the retina called?

Q. Identify the part of the human eye on which different images are formed.

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

Q. Presbyopia is caused due to the weakening of

1. ciliary muscles
2. retina
3. eye lens
4. iris

Q.

What is the circular opening in the middle of iris known as?

1. Pupil

2. Cornea

3. Lens of the eye

4. Retina

Q.

What is meant by 'persistence of vision'?

Q. The part of the eye functioning to refract light is:

1. Crystalline lens
2. Aqueous humor
3. Iris
4. Cornea

Q.

A blind person can never read and write.

1. True

2. False

Q.

What is the portion of the eye called where there are no sensory cells to support vision? [2 MARKS]

Q.

Give scientific reasons for the following statement.

We cannot distinguish colours in moonlight.

Q.

The change in converging power of an eye-lens is caused by the action of:

(a) iris

(b) ciliary muscles

(c) optic nerve

(d) retina

Q.

Name the phenomenon which enables us to see movies in a cinema hall.

Q. ___ protects our eyes from dust particles entering the eyes.

1. Pupil
2. Retina
3. Cornea
4. Eyelids