Advertisements
Advertisements
Question
Answer briefly:
How do you perceive the colour of an object?
Solution
Photoreceptors are cells that are sensitive to light. They are of two types – rods and cones. These are present in the retina. Cones help in distinguishing colours. There are three types of cone cells – those responding to green light, those responding to blue light, and those responding to red light. These cells are stimulated by different lights, from different sources. The combinations of the signals generated help us see the different colours.
APPEARS IN
RELATED QUESTIONS
Night birds have ______ cones than rods in their eyes.
The optical prescription for a pair of spectacles is :
Right eye : −3.50 D
Left eye : −4.00 D
Which lens has a greater focal length?
Name the part of the eye:
which controls the amount of light entering the eye.
State whether the following statement is true or false:
The image formed on our retina is upside-down
How is the amount of light entering the eye controlled?
A person walking in a dark corridor enters into a brightly lit room:
State the effect on the pupil of the eye.
Ciliary muscles of human eye can contract or relax. How does it help in the normal functioning of the eye?
Which of the following controls the amount of light entering the eye?
(a) ciliary muscles
(b) lens
(c) iris
(d) cornea
How does the eye change in order to focus on near or distant objects?
(a) The lens moves in or out
(b) The retina moves in or out
(c) The lens becomes thicker or thinner
(d) The pupil gets larger or smaller
The size of the pupil of the eye is adjusted by:
(a) cornea
(b) ciliary muscles
(c) optic nerve
(d) iris
The descriptions of five kinds of images are given below:
(a) diminished and virtual
(b) enlarged and real
(c) enlarged and erect
(d) real and inverted
(e) virtual and the same size
Which one of these describes the image formed:
(i) on the retina of the eye?
(ii) by a magnifying glass?
(iii) by a convex driving mirror on a car?
(iv) by a plane mirror?
(v) on the screen of a slide projector?
Mention, where in living organism is the following located and state their main function:
Fovea centralis
Name the following:
The opening through which light enters the eyes.
Answer the following question.
Write the structure of eye lens and state the role of ciliary muscles in the human eye.
What is the nature of the image that forms on the retina?
What kind of lens is there in our eyes? Where does it form the image of an object?
Which one of the following statements is NOT correct?
Given below is a cross section of the human eye. Match the structures marked (a) to (e) with their correct functions:
Example: (f) - 6. Holds the lens in position
| Cross section of Human Eye | Functions | |
 |
1. | Protects retina |
| 2. | Regulates the size of the pupil | |
| 3. | Alters the shape of the lens | |
| 4. | Keeps the lens moist | |
| 5. | Transmits nerve impulses to brain | |
| 6. | Holds the lens in position |
Name the following:
The circular opening enclosed by iris.
