Question

The eye can be regarded as a single refracting surface . The radius of curvature of this surface is equal to that of cornea ($7.8\, mm$ ). This surface separates two media of refractive indices 1 and $1.34$. Calculate the distance from the refracting surface at which a parallel beam of light will come to focus.

• A. $2\, cm$
• B. $1 \,cm$
• C. $3.1\, cm$
• D. $4.0\, cm$

Answer 1

Answer: (C)

$3.1\, cm$

Answer 2

$\frac{1.34}{V} - \frac{1}{\infty} = \frac{1.34-1}{7.8}$ $\therefore V= 30.7\, mm$