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प्रश्न
What is the function of iris and the muscles connected to the lens in human eye?
उत्तर
- Function of Iris: The iris is a muscular diaphragm that controls the size of the pupil, which, in turn, controls the amount of light entering the eye. It also gives color to the eye.
- Function of ciliary muscles: The ciliary muscles hold the eye lens in position and adjust its focal length by expanding and contracting.
APPEARS IN
संबंधित प्रश्न
Write the function of the following part of the human eye: Cornea
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
Night birds have ______ cones than rods in their eyes.
A person got his eyes tested by an optician. The prescription for the spectacle lenses to be made reads :
Left eye : +2.50 D
Right eye : +2.00 D
State whether these lenses are thicker in the middle or at the edges.
What is the principal function of the eye-lens?
What changes the shape of lens in the eye?
Give the scientific names of the following parts of the eye:
changes shape to focus a picture on the retina.
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.
A person walking in a dark corridor enters into a brightly lit room:
State the effect on the pupil of the eye.
Name the cells on the retina of an eye which are sensitive to (i) bright light (ii) dim light (iii) sensation of colour.
Which part brings the image into sharp focus on the retina? How does it do this?
Out of animals of prey and predators, which have their eyes:
on the opposite sides of their head?
Mention if the following statement is true (T) or false (F) Give reason.
Sometimes medicines dropped into the eyes come into the nose and even throat
Mention if the following statement is true (T) or false (F) Give reason.
yellow spot of the retina is the region of colour vision
Given below is certain structure. Write against them its functional acivity.
retina and ……………………….
With reference to the functioning of the eye, answer the question that follow:
What is the shape of the lens during near vision?
Choose the correct answer.
Colour is detected by ____________
Differentiate between:
Vitreous humour and Aqueous humour.
Mention, if the following statement is True or False
Rods are responsible for vision in the dark
State the Function:
Vitreous humour
Long answer question
Draw the neat labelled diagram of the Sectional view of the human eye.
Write an Explanation.
Minimum distance of distinct vision
Write an Explanation.
Farthest distance of distinct vision
Draw the struture of human eye and label its parts.
The image formed on the retina of the human eye is ____________.
When light rays enter the eye, most of the refraction occurs at the ____________.
A tiny mirror M is fixed on a piece of cardboard placed on a table. The cardboard is illuminated by light from a bulb. The position of eye with respect to position of bulb is shown in the figure as A, B, C and D. In which position mirror will be visible?
 |
 |
 |
 |
| (A) | (B) | (C) | (D) |
Write down the names of parts of the eye in the blank spaces shown in the figure.
Which one of the following statements is NOT correct?
Vitreous humour is present between ______.
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 | 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 | Hypermetropoia | e | Power of accomodation |
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 | 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 accomadation |
Name the following:
Place of no vision in the retina of the eye.
Name the following:
The circular opening enclosed by iris.
Name the following:
Two pigments of the sensory cells.
