Advertisements
Advertisements
Question
the biological/technical terms for the lens of eye losing flexibility resulting in a kind of long-sightedness in middle aged people.
Solution
The lens of eye losing flexibility resulting in kind of long-sightedness in middle aged people – Presbyopia
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.
What is myopia?
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 near point is more than 25 on away.
What is the other name for
hypermetropia
What are the two most common defects of vision (or defects of eye)? How are they corrected?
Explain with the help of labelled ray diagram, the defect of vision called myopia and how it is corrected by a lens.
Differentiate between members of the following pair with reference to what is asked in bracket.
Myopia and hyperopia (cause of the defect)
Explain the terms ‘adaptation’ and ‘accommodation’ with reference to the eye.
Enumerate the common defects of vision, their causes and the possible methods of correcting them.
A person is unable to see distinctly the objects closer than 1 m. Name the defect of vision he is suffering from. Draw ray diagrams to illustrate the cause of the defect and its correction by suitable lens.
An old man cannot see objects closer than 1 m from the eye clearly. Name the defect of vision he is suffering from. How can it be corrected? Draw ray diagram for the (i) defect of vision and also (ii) for its correction.
What eye defect is hypermetropia? Describe with a ray diagram how this defect of vision can be corrected by using an appropriate lens.
Name the following:
The photosensitive pigment present in the rod cells of the retina.
Explain the Term: Presbyopia
Name the following:
The defect of the human eye caused due to the uneven surface of the cornea.
Give Technical Term:
The type of lens used to correct myopia is
In Myopia the human eye _______.
Due to elongation of _______ and increase in curvature of the eye lens, a person cannot see distant objects clearly.
A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power:
