Question

The resolving power of human eye is:
A. $\approx \text{1'}$
B. $\approx \text{ 1}{}^\circ$
C. $\approx \text{ 10''}$
D. $\approx \text{ 5''}$

Answer 1

Hint: To find the resolving power of the human eye, we need to be clear about the definition of resolving power. The visibility of the human eye is limited up to a distance. This concept will be a great help in answering the question.

Complete step by step answer:
  It is known to us that the normal pupil size of any human being is 4 mm. This measurement sets a minimum resolution approximately $\text{{1}'}$ to ${2}'$. When we want to pull small objects closer to our eyes, we aim to see them properly. But it is often seen that after crossing a certain distance the particles become unclear no matter how much closer it is to our eyes. This signifies that there is a minimum distance of comfortable viewing. This distance is roughly calculated as 25 cm.
Therefore, the correct answer to the question is Option A.
Additional Information: The resolving power of a microscope is the most important feature in case of an optical system. This is important because it influences the ability to distinguish between fine details of a particular specimen. When we talk about the resolving power of a microscope or telescope, we mean its ability to distinguish between two images when they are brought close together.
Note: By resolving power, we mean the ability of the eye or it can be for any optical instrument to be able to differentiate between two points or lines. This is typically expressed as an angle of separation which is radiating outward from the eye of the instrument taken into consideration.
When compared to that of a compound microscope, the resolving power of the human eye is up to 200 micrometers whereas, in case of a compound microscope, it is 0.2.