Question

The eye can be regarded as a single refracting surface. The radius 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

$\frac{1.34}{V}-\frac{1}{\infty }=\frac{1.34-1}{7.8}$

$\frac{1.34}{v}=\frac{34}{780}$

$v=\frac{1.34\times 780}{34}$
$\therefore V=30.7mm$