Question

24 Manu had some trouble with his eye sight and went to the eye doctor. The doctor prescribed
negative power lens.
a) What defect of the eye is Manu suffering from?
b) What is the focal length of the lens if its power is -3.5D?
c) Why is Manu suffering from this problem?

Answer 1

Answer:

1). Manu is suffering from Myopia or short-sightdness. In this the person is unable to see distant objects clearly.

2). If Power is -3.5D then the focal length is 0.28m or 28 cm.

3). Manu is suffering form this problem due to two main reason:-

i. the eye ball is lengthened from front to back

ii. the lens is too curved

Answer 2

Before moving to the question, lets get the definition of some problems.

MYOPIA:-

This is the long distance sightedness defect,where any Person is not able to see distance objects.

Hypermetropia:-

This is the short distance sightedness defect,where people can see distance object but not short distance.

NOW,

COMING TO THE QUESTION.

manu is suffering from which disease?

He is suffering from MYOPIA

long distance sightedness defect.

He is not able to view distant objects.

2) F=1/D

=>F=1/3.5

=>2/7 u

is the focal length.

3) Manu is suffering from this disease because he has a deficiency of vitamin A.

and he need vitamin a supplements.

ans.