Assuming human pupil to have a radius of 0.25 cm and a comfortable viewing distance of 25 cm, the minimum separation between two objects that human eye can resolve at 500 nm wavelength is :
Radius of human solution pupil=0.25cm or diameter =0.5cm=5x10-3m
Since
The distance of comfortable viewing =25cm
Let x be the minimum separation between the two object that the human eye can resolve them