English
Maharashtra State BoardSSC (English Medium) 10th Standard

Observe the given below the figure, correct it and explain and write about the concept depicted in this figure.

Advertisements
Advertisements

Question

Observe the given below the figure, correct it and explain and write about the concept depicted in this figure.

Short/Brief Note
Advertisements

Solution

The figure shows a myopic eye, in which the eye lens is unable to focus the light rays coming from distant object onto the retina. In this defect, the image of distant object is formed before the retina i.e., the light rays converge before they reach the retina. Hence, to correct this defect a diverging lens (concave lens) of proper focal length is used, so that, the rays reach the retina after refraction and the person can see the image clearly.

shaalaa.com
  Is there an error in this question or solution?
Chapter 7: Lenses - Answer the Following

RELATED QUESTIONS

Given below is a diagram showing a defect of human eye. Study it and answer the following questions.

(i) Name the defect shown in the figure.
(ii) Give reason for this defect of eye in human being.
(iii) Name the type of lens used to correct the eye defect.


A student is unable to see clearly the words written on the blackboard placed at a distance of approximately 4 m from him. Name the defect of vision the boy is suffering from. Explain the method of correcting this defect.

Draw ray diagram for the:-

(i) defect of vision and also

(ii) for its correction.


Name the defect of vision in a person: 

whose far point is less than infinity


Which defect of vision can be rectified: 

 by using a convex lens?


What is the scientific name of 

short-sightedness


Name the defect of vision which makes the eye-lens cloudy resulting in blurred vision.


What is the far point of a person suffering from myopia (or short-sightedness)?


Your friend can read a book perfectly well but cannot read the writing on blackboard unless she sits on the front row in class. 

 What type of lenses-converging or diverging-would an optician prescribe for her?


A man can read the number of a distant but clearly but he finds difficulty in reading a book. 

 From which defect of the eye is he suffering?


A person suffering from the eye-defect myopia (short-sightedness) can see clearly only up to a distance of 2 metres. What is the nature and power of lens required to rectify this defect?


An eye has a far point of 2 m. What type of lens in spectacles would be needed to increase the far point to infinity?  Also calculate the power of lens required. Is this eye long-sighted or short-sighted?


A person cannot see the distant objects clearly (though he can see the nearby objects clearly). He is suffering from the defect of vision called:
(a) cataract
(b) hypermetropia
(c) myopia
(d) presbyopia


A person can read a book clearly only if he holds it at an arm's length from him. Name the defect of vision:  

if the person is a young man 


Which part of the eye is grafted in a needy patient from a donated eye?


Name the following:

The eye defect caused due to shortening of the eye ball from front to back.


A person is unable to read a book placed closer than 1 meter from his eyes. Identify the defect of vision in his eyes. Draw the ray diagrams to show the defect of vision and its correction.


A student cannot see a chart hanging on a wall placed at a distance of 3 m from him. Name the defect of vision he is suffering from. How can it be corrected? Draw ray diagrams for the (i) defect of vision and also (ii) for its correction.


List two causes of presbyopia. Draw labelled diagram of a lens used for the correction of this defect of vision. 


When do we consider a student sitting in the class to be myopic? List two causes of this defect. Explain using a ray diagram how this defect of eye can be corrected.


Given below is a diagram depicting a defect of the human eye? Study the same and answer the question that follow:

Give two possible reasons for this defect of the eye in human beings.


Have a look at the posture of this woman who is reading a book and answer the questions which follow:

What are the two conditions shown in sections A and B of the eye as applicable to her?


Anuja cannot see the blackboard writing but she can see nearby things.
(a) What is the eye defect she is suffering from?
(b) State the possible reason for her defect.
(c) How is it corrected


Give Reason:

Older people require glasses to read and write.


Give Reason:

Deficiency of vitamin A causes night blindness.


Give Reason:

When you enter into a dark room from bright because of sunlight, you can not see things for a few seconds.


Explain the Term: Presbyopia


Explain the Term: Astigmatism


What type of lens is used to correct Astigmatism?


Given below is a diagrammatic representation of a defect of the human eye:

(i) Identify the defect.
(ii) Mention two reasons for the above defect.
(iii) State how the defect can be rectified.
(iv) Name the part of the eye responsible for maintaining the shape of the eyeball.


With respect to human eye explain:
(i) How is the image formed on the retina?
(ii) How is the amount of light entering the eye-controlled?
(iii) What type of lens is used for the correction of ‘Long sight’ defect?
(iv) With the help of a ray, diagram show the defect of the eye and then its correction after the use of a lens.


Mention, if the following statement is True or False
Hypermetropia is a defect of the eye caused due to the eyeball elongation


 Choose the Odd One Out: 


Nearsightedness: elongated eyeball : : farsightedness: _______


Given below is a diagram showing a defect of vision. Name the defect of vision and draw an accurately labelled diagram to correct this defect.


A person needs a lens of power –4.5 D for correction of her vision.

  1. What kind of defect in vision is she suffering from?
  2. What is the focal length of the corrective lens?
  3. What is the nature of the corrective lens?

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

Given alongside is a diagram depicting a defect of the human eye. Study the same and answer the questions that follow:

  1. Name the defect shown in the diagram.
  2. Give two possible reasons for this defect.
  3. Name the parts labelled 1 to 4.
  4. Name the type of lens used to correct this eye defect.
  5. Draw a labelled diagram to show how the above mentioned defect is rectified using the lens named above.

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×