Defects of Vision
Physics ⇒ Light and Optics
Defects of Vision starts at 9 and continues till grade 12.
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See sample questions for grade 9
A person can see objects clearly only when they are between 50 cm and 2 m from the eye. What type of vision defect does the person have?
A person is unable to read a book held at normal reading distance but can see distant objects clearly. What defect does the person have?
A person with a near point of 50 cm wants to read a book at 25 cm. What type of lens should be used?
A person with astigmatism sees vertical lines clearly but horizontal lines are blurred. What type of lens should be used to correct this?
A person with hypermetropia has a near point at 75 cm. What type of lens should be used to correct this defect?
A person with presbyopia may also have myopia. What type of lens is used in such cases?
Describe how a concave lens corrects myopia.
Describe how bifocal lenses help people with presbyopia.
Explain the cause of myopia in the human eye.
Explain why a person with myopia cannot see distant objects clearly.
Explain why presbyopia often requires bifocal lenses for correction.
Name the defect of vision caused by the irregular curvature of the cornea or lens.
State one main difference between myopia and hypermetropia.
What is the function of the retina in the human eye?
What is the main cause of presbyopia?
What is the term used for the inability to see distant objects clearly?
Which lens is used to correct myopia?
Which part of the eye changes its shape to focus on near or distant objects?
