Advertisements
Advertisements
प्रश्न
Name an old age eye defect. Why is it caused?
Advertisements
उत्तर १
Presbyopia is an age-old eye defect. In this condition, the lens loses flexibility resulting in far-sightedness.
Cataract is also very common in old people, the cornea becomes opaque and the vision is cut down even to blindness.
उत्तर २
Hypermetropia. It is caused due to flattening of the eye lens (Also presbyopia in which lens looses flexibility).
APPEARS IN
संबंधित प्रश्न
What is the scientific name of
short-sightedness
What is the scientific name of
long-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 student sitting in the last row of the class-room is not able to read clearly the writing on the blackboard.
Name the type of defect he is suffering from.
Differentiate between members of the following pair with reference to what is asked in the bracket.
Rods and cones (sensitivity).
Given alongside is a diagram depicting a defect of the human eye. Study the same and then answer the questions that follow:
(i) Identify the defect.
(ii) Name the parts labelled 1, 2 and 3.
(iii) Give labelled two possible reasons for this eye defect.
(iv) Draw a labelled diagram to show how the above mentioned defect is rectified.

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?
The diagram given below represents the cross-section of the human eye:

(i) Name the parts labeled 1—12.
(ii) What is the function of the part marked ‘10’?
(iii) What would happen if part ‘5’ is damaged or cut?
Choose the Odd One Out:
Observe the figure whether it is correct or not and explain the phenomenon.

