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प्रश्न
Write scientific reason.
The movie cannot be enjoyed if seat of a viewer is too close to the screen in the cinema.
उत्तर
- The nearer someone is sitting to the screen of the cinema hall; the more is the intensity of light falling on the eye.
- Thus, the pupil has to contract a lot, which causes a strain in the eye.
Hence, one cannot enjoy watching a movie from a very short distance from the screen in a cinema hall.
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संबंधित प्रश्न
The region of the vertebrate eye, where the optic nerve passes out of the retina, is called the
(a) fovea
(b) iris
(c) blind spot
(d) optic chaisma
How does the eye adjust to take account of an increase in brightness?
What do the ciliary muscles do when you are focusing on a nearby object?
Give the scientific names of the following parts of the eye:
muscles which change the shape of the eye-lens.
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.
Refraction of light in the eye occurs at:
(a) the lens only
(b) the cornea only
(c) both the cornea and the lens
(d) the pupil
The term " accommodation" as applied to the eye, refers to its ability to:
(a) control the light intensity falling on the retina
(b) erect the inverted image formed on the retina
(c) vary the focal length of the lens
(d) vary the distance between the lens and retina
Which of the following changes occur when you walk out of bright sunshine into a poorly lit room?
(a) the pupil becomes larger
(b) the lens becomes thicker
(c) the ciliary muscle relaxes
(d) the pupil becomes smaller
Explain why, when it is getting dark at night, it is impossible to make out the colour of cars on the road.
Nocturnal animals (animals which sleep during the day and come out at night) tend to have wide pupils and lot of rods in their retinas. Suggest reasons for this.
Name two animals having eyes:
one the sides of the head.
Name the following:
The photoreceptors found in the retina of the eye.
With reference to the functioning of the eye, answer the question that follow:
Name the cells of the retina and its respective pigments which get activated in the light.
Write whether the following is true or false:
Rods are the receptor cells in the retina of the eye sensitive to dimlight.
Choose the correct answer.
In the chemistry of vision, the photosensitive substance is _________________
What happens to the image distance in the normal human eye when we decrease the distance of an object, say 10 m to 1 m? Justify your answer.
Differentiate between:
Vitreous humour and Aqueous humour.
Give Technical Term:
The adjustment of the eye in order to obtain a clear vision of objects at different distances
State the Function:
Ear drum
State the Function:
Conjunctiva
Complete the following sentence with appropriate Word
The part of the human eye where rod cells and cone cells are located is the:
Long answer question
Draw the neat labelled diagram of the Sectional view of the human eye.
Vision defect that increases distance between the lens of the eye and retina of the eye is termed as myopia.
Why the human eye is compared with camera?
The pigmented circular area seen in front of the eye:
______ is a transparent layer.
The transparent membrane that keeps the eye moist is ______.
Which cells of the retina enable us to see coloured objects around us?
Match the following:
| Column - I | Column - II |
| 1. Retina | a) Path way of light |
| 2. Pupil | b) Far point comes closer |
| 3. Ciliary muscles | c) near point moves away |
| 4. Myopia | d) Screen of the eye |
| 5. Hypermetropia | e) Power of accommodation |
Match the following:
| Column - I | Column - II | ||
| 1 |
Retina |
a | Pathway of light |
| 2 | Pupil | b |
Far point comes closer |
| 3 | Ciliary muscles | c |
near point moves away |
| 4 | Myopia | d | Screen of the eye |
| 5 | Hypermetropia | f | Power of accommodation |
With reference to human eye, answer the following question.
What is blind spot?
Match the following:
| Column - I | Column - II |
| 1. Retina | a. Pathway of light |
| 2. Pupil | b. Far point comes closer |
| 3. Ciliary muscles | c. near point moves away |
| 4. Myopia | d. Screen of the eye |
| 5. Hypermetropia | f. Power of accommodation |
Match the following:
| Column - I | Column - II | ||
| 1 | Retina | a | pathway of light |
| 2 | Pupil | b |
far point comes closer |
| 3 | Ciliary muscles | c |
near point moves away |
| 4 | Myopia | d | screen of the eye |
| 5 | Hypermetropia | e | power of accommodation |
Name the following:
The circular opening enclosed by iris.
Name the following:
The fibres which collectively hold the lens in position.
Write the main functional activity of the following structure.
Ciliary body and suspensory ligament
