Myopic person uses spectacles of power – 1.0 dioptre or concave lens of focal length f =

1

P

= - 100 cm in order to observe clearly object at infinity.
Far point of the person can be calculated as

1

v

−

1

u

=

1

f

or

1

v

−

1

−∞

=

1

−100

or v = - 100 cm
Similarly if the person uses spectacles of power + 2.0 dioptre then he must be using convex lens of power + 2.0 dioptre.
Focal length and near point can be calculated as
f =

1

p

=

1

+2

= 0.5 m = 50 cm
For near point,

1

v

−

1

u

=

1

f

1

v

−

1

−25

=

1

50

or

1

v

=

1

50

−

1

25

⇒

1

v

=

1−2

50

or v = - 50 cm
Thus the person also has the defect of hypermetropia and has a near point 50 cm. So having both defects he needs different lenses for distant vision and to see closer objects.