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प्रश्न
What type of lens is used to correct Astigmatism?
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उत्तर
Cylindrical lens
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संबंधित प्रश्न
A person suffering from the eye-defect myopia (short-sightedness) can see clearly only up to a distance of 2 metres. What is the nature and power of lens required to rectify this defect?
The near-point of a person suffering from hypermetropia is at 50 cm from his eye. What is the nature and power of the lens needed to correct this defect? (Assume that the near-point of the normal eye is 25 cm).
A person cannot see the distant objects clearly (though he can see the nearby objects clearly). He is suffering from the defect of vision called:
(a) cataract
(b) hypermetropia
(c) myopia
(d) presbyopia
Differentiate between members of the following pair with reference to what is asked in the bracket.
Rods and cones (sensitivity).
State the main functions of the following:
Tears
Give Reason:
Deficiency of vitamin A causes night blindness.
Draw a neat labeled diagram to show how hypermetropia can be rectified.
Explain the Term: Hypermetropia
Choose the Odd One Out:
When do we consider a person to be myopic or hypermetropic? Explain using diagrams how the defects associated with myopic and hypermetropic eye can be corrected?
