Advertisements
Advertisements
Question
What type of lens is used to correct Hypermetropia?
Advertisements
Solution
Convex lens
APPEARS IN
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.
Millions of people in the developing countries of the world are suffering from corneal blindness. These persons can be cured by replacing the defective cornea with the cornea of a donated eye. A charitable society of your city has organised a campaign in your neighbourhood in order to create awareness about this fact. If you are asked to participate in this mission, how would you contribute in this noble cause?
(i) State the objective of organising such campaigns.
(ii) List two arguments which you would give to motivate the people to donate their eyes after death.
(iii) List two values which are developed in the persons who actively participate and contribute in such programmes.
A person with a myopic eye cannot see objects beyond 1.2 m distinctly. What should be the type of the corrective lens used to restore proper vision?
Name the defect of vision in which the eye-lens loses its power of accommodation due to old age.
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
Describe the mechanism of focusing the image of a distant object in your eye when you raise your head after reading a book.
Rewrite the following table so as to match second and third column with first column.
|
Column I
|
Column II
|
Column III
|
|
(i) Myopia
|
Old age problem
|
Bifocal lens
|
|
(ii) Presbyopia
|
Nearsightedness
|
Concave lens.
|
Nearsightedness: elongated eyeball : : farsightedness: _______
Observe the given below the figure, correct it and explain and write about the concept depicted in this figure.

Myopia may arise due to ____________.
