a) The near point of a hypermetropic person is 75cm from the eye. What is the power of the lens requiredto enable the person to read clearly a book held at 25cm from the eye. (b ) In what way does the corrective lens help the above person? Does the lens magnify objects held near the eye? c) The above person prefers to remove the spectacles while looking at the sky. Explain why?

a) The near point of a hypermetropic person is 75cm from the eye. What

1.	a) The near point of a hypermetropic person is 75cm from the eye. What is the power of the lens requiredto enable the person to read clearly a book held at 25cm from the eye. (b ) In what way does the corrective lens help the above person? Does the lens magnify objects held near the eye? c) The above person prefers to remove the spectacles while looking at the sky. Explain why?
Answer» Solution :a) `u=0.25m,v=0.75m, F=?` `1/F=1/v-1/4` Power `P=-1/0.75+1/0.25=(-100)/75+100/25=(-4)/3+4` P=2.67D (b ) The corrective lens PRODUCES a virtual IMAGE (at 75 cm) of an object at 25cm). The ANGULAR size of this image is the same as the object. In this sense, the lens does not magnify the object but merely brings the object to the near point of the hypermetropic eye which then gets focused on the retina. C) A hypermetropic eye may have normal far point i.e., it may have enough converging power to focus parallel rays from infinity on the retina of the SHORTENED eyeball.