Abstract

This essay endeavours to find out “how the resolving power of the eye is affected by the size of the pupil”. According to the Rayleigh criterion the resolving power should get greater as the pupil size increases. An experiment was carried out in an attempt to measure the resolving power at different pupil sizes; this was problematic since to change the pupil size meant changing the light intensity. To achieve this without altering the light illuminating the object a black tube was applied to the eye, this gave a result but it was not possible to measure the actual size of the pupil. The results showed that the resolving power actually increases with decreasing pupil size.  This is thought to be due to other factors that outweigh the diffraction effect namely defects of the lens and the distribution of the light sensitive cells on the retina.