English
Maharashtra State BoardSSC (English Medium) 10th Standard

What is Myopia?

Advertisements
Advertisements

Question

What is myopia?

Advertisements

Solution

Myopia or near-sightedness is the defect of vision in which a human eye can see nearby objects distinctly but is unable to see distant objects clearly. In this case, the image of a distant object is formed in front of the retina instead of on the retina.

 

shaalaa.com
  Is there an error in this question or solution?
2012-2013 (March)

APPEARS IN

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.


What is the far point and near point of the human eye with normal vision?


the biological/technical terms for the lens of eye losing flexibility resulting in a kind of long-sightedness in middle aged people.


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 concave lens?


Which defect of vision can be rectified: 

 by using a convex lens?


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


Name any two defects of vision which can be corrected by using spectacles.


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

  1. Is she short-sighted or long-sighted?
  2. What type of lenses-converging or diverging-would an optician prescribe for her?

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

  1. From which defect of the eye is he suffering?
  2. What type of spectacle lens should he use to correct the defect?

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

What type of spectacle lens should he use to correct the  defect?


Differentiate between myopia and hypermetropia.


Explain with the help of labelled ray diagram, the defect of vision called myopia and how it is corrected by a lens.


The near-point of a person suffering from hypermetropia is at 50 cm from his eye. What is the nature and power of the lens needed to correct this defect? (Assume that the near-point of the normal eye is 25 cm).


 A person having short-sight cannot see objects clearly beyond a distance of 1.5 m. What would be the nature and power of the corrective lens to restore proper vision?


The picture given here shows a person wearing ‘half-moon’ spectacles. What sort of eye-defect do you think he has? Why are these particular spectacles useful to him?


A short-sighted person has a near point of 15 cm and a far point of 40 cm.
(a) Can he see clearly an object at a distance of:
(i) 5 cm?
(ii) 25 cm?
(iii) 50 cm?
(b) To see clearly an object at infinity, what kind of spectacle lenses does he need?


Name an old age eye defect. What happens in it?


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

Name the defect shown in the diagram.


State the main functions of the following: 
 Tears 


Write whether the following is true or false:
A convex lens is used for correcting myopia.


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

  1. Identify the defect.
  2. Name the parts labelled 1, 2 and 3.
  3. Give two possible reasons for this eye defect.
  4. Draw a labelled diagram to show how the above mentioned defect is rectified.

Name the cells of the retina that are sensitive to colours.

Choose the correct answer : 
Presbyopia is a disease of _____________


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

Name the type of lens used to correct this eye defect.


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

What kind of looking glasses she needs?


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


Name an old age eye defect. Why is it caused?


Complete the following sentence with appropriate word :
An inability to focus on nearby objects due to loss of elasticity of the lens with age is called Iris.


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


In Myopia the human eye _______.


Due to elongation of _______ and increase in curvature of the eye lens, a person cannot see distant objects clearly.


Nearsightedness : concave lens : : farsightedness : _______


Write scientific reason.

Nearsightedness, this defect can be corrected by using spectacles with concave lens.


Which of the following statement is correct?


A person is unable to see clearly a poster fixed on a distant wall. He however sees it clearly when standing at a distance of about 2 m from the wall.

  1. Draw ray diagram to show the formation of image by his eye lens when he is far away from the wall.
  2. List two possible reasons of this defect of vision.
  3. Draw ray diagram to show the correction of this defect using appropriate lens.

Complete the following table by observing the given figures:

Figure
Points
(a) Name of the defect ______ ______
(b) Position of the image ______ ______
(c) Lens used to correct the defect ______ ______

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×