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Question
Which defect of vision can be rectified:
by using a convex lens?
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Solution
Hypermetropia can be rectified by using convex lenses.
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RELATED QUESTIONS
In a Std. X class out of 40 students 10 students use spectacles, 2 students have positive power and 8 students have negative power of lenses in their spectacles.
Answer the following questions:
(1) What does the negative power indicate?
(2) What does the positive power indicate?
(3) Generally which type of spectacles do most of the students use?
(4) What defect of eyesight do most of the students suffer from?
(5) Give two possible reasons for the above defect.
What is the scientific name of
long-sightedness?
Name the body part with which the terms myopia and hypermetropia are connected.
A student sitting in the last row of the class-room is not able to read clearly the writing on the blackboard.
How can this defect by corrected?
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?
Explain the terms ‘adaptation’ and ‘accommodation’ with reference to the eye.
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.
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.
Distinguish between the following pair of words:
Myopia and hypermetropia
Write whether the following is true or false:
A convex lens is used for correcting myopia.
Given below is a diagram depicting a defect of the human eye? Study the same and answer the question that follow:
Name the parts labeled 1 to 4.
The near point of the eye of a person is 50 cm. Find the nature and power of the corrective lens required by the person to enable him to see clearly the objects placed at 25 cm from the eye?
A person is unable to see objects distinctly placed within 50 cm from his eyes.
(a) Name the defect of vision the person is suffering from and list its two possible causes.
(b) Draw a ray diagram to show the defect in the above case.
(c) Mention the type of lens used by him for the correction of the defect and calculate its power. Assume that the near point for the normal eye is 25 cm.
(d) Draw a labeled diagram for the correction of the defect in the above case.
Give Reason:
Why do we see clearly in the central region of the retina?
Give Technical Term:
The path which responsible for protecting the eye from sweat.
Choose the Odd One Out:
Observe the given below the figure, correct it and explain and write about the concept depicted in this figure.
Draw ray diagram showing myopic eye.
