If the far point of eye lens is 10 m, find power of the lens required

1.	If the far point of eye lens is 10 m, find power of the lens required to correct the defect.
Answer» Far point of the eye lens = v v = -10 m Object distance = u u = ∞ Lens Formula: \(\frac{1}{f}\,=\,\frac1v\,=\,\frac1u\) \(\frac1f\,=\,\frac1{-10}\,-\,\frac1{∞}\) Power of lens, P = 1/f = -10 D Hence the power of the lens required to correct the defect is -10 D. The lens used is a concave lens.

If the far point of eye lens is 10 m, find power of the lens required to correct the defect.

Answer»

Far point of the eye lens = v

v = -10 m

Object distance = u

u = ∞

Lens Formula:

\(\frac{1}{f}\,=\,\frac1v\,=\,\frac1u\)

\(\frac1f\,=\,\frac1{-10}\,-\,\frac1{∞}\)

Power of lens, P = 1/f

= -10 D

Hence the power of the lens required to correct the defect is -10 D. The lens used is a concave lens.