Question -
Answer -
The power of the spectacles used by themyopic person, P = −1.0 D
Focal length of the spectacles, 
Hence, the far point ofthe person is 100 cm. He might have a normal near point of 25 cm. When he usesthe spectacles, the objects placed at infinity produce virtual images at 100cm. He uses the ability of accommodation of the eye-lens to see the objectsplaced between 100 cm and 25 cm.
Duringold age, the person uses reading glasses of power,
Theability of accommodation is lost in old age. This defect is called presbyopia.As a result, he is unable to see clearly the objects placed at 25 cm.