Thank you for reporting, we will resolve it shortly
Q.
A hypermetropic person has to use a lens of power $+5\, D$ to normalise his vision. The near point of the hypermetropic eye is
Ray Optics and Optical Instruments
Solution:
We have, $f=\frac{1}{P}=\frac{1}{5} m =20\,cm$
Now, $\frac{1}{v}-\frac{1}{u}=\frac{1}{20} $ (from lens formula)
Or $\frac{1}{v}-\frac{1}{-25}=\frac{1}{20}$
or $\frac{1}{v}=\frac{1}{20}-\frac{1}{25}$
Or $\frac{1}{v}=\frac{5-4}{100}$ or $\frac{1}{v}=\frac{1}{100}$
Or $d=100 \,cm =1 \,m$