Question

The diameter of the pupil of human eye is about 2 mm. Human eye is most sensitive to the wavelength of 555 nm. The limit of resolution of human eye is:

• A. 1.2 min
• B. 2.4 min
• C. 0.6 min
• D. 0.3 min

Answer 1

Answer: (A)

1.2 min

Limit of resolution
$d\theta =\frac{1.22\lambda }{D}=\frac{1.22\times 555\times {10}^{-9}}{2\times {10}^{-3}}$ = 3.39 $\times {10}^{-4}$ rad

$d\theta =3.39\times {10}^{-4}\times \left[\frac{{180}^{\circ }}{\pi }\right]$

$={0.0194}^{\circ }=0.0194\times 60min=1.2min$