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प्रश्न
Give Reason:
Why do we see clearly in the central region of the retina?
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उत्तर
The central region of the retina has fovea centralis, with the yellow spot area surrounding it. There are only cone cells responsible for clear vision and details of the objects.
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संबंधित प्रश्न
Which defect of vision can be rectified:
by using a convex lens?
What is the scientific name of
long-sightedness?
Name the defect of vision in which the eye-lens loses its power of accommodation due to old age.
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.
What type of lenses-converging or diverging-would an optician prescribe for her?
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.
|
Name the following:
The defect of the human eye caused due to the uneven surface of the cornea.
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.
Nearsightedness : concave lens : : farsightedness : _______
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 | ______ | ______ |
