Question

When viewing through a compound microscope, our eyes should be positioned not on the eyepiece but a short distance away from it for best viewing. Why?How much should be that short distance between the eye and eye-piece?

Answer 1

The classic compound microscope magnifies in two steps: first with an objective lens in a 'real' image plane that generates an enlarged image of the object. To produce the virtual image, this real image is then magnified by the ocular lens or eyepiece. A microscope can be formed from two convex lenses.

Complete answer:
We are unable to capture much reflected light when we position our eyes too close to the eyepiece of a compound microscope. As a result, the field of view decreases dramatically. Thus, the image's visibility gets distorted,
At the eye-ring attached to the ocular, the optimal location of the eye for viewing through a compound microscope is. The exact placement of the eye depends on the separation between the lens of the object and the eyepiece.

Additional information:
In order to give a total magnification of 1,000, the magnification of a compound optical microscope is the product of the magnification of the ocular (say 10x) and the objective (say 100x) lens. Modified conditions can increase magnification, such as the use of oil or ultraviolet light.
As the picture is produced in the centre of a brightly illuminated area, the popular light microscope is often called a bright-field microscope. Since the specimen or object is denser and more opaque than the surroundings, the picture appears darker. Part of the light that travels into or through the material is absorbed.

Note:
The light from the illuminator passes through the aperture, through the slide, and through the objective lens, where the image of the specimen is magnified. The magnified image then travels up to the eyepiece through the microscope's body tube, which further magnifies the image that the spectator sees.