Therefore, it is an ideal position for our eyes for viewing If we place our eyes too close to the eye-piece, we shall not collect
much of the light and also reduce our field of view If we position
our eyes on the eye-ring and the area of the pupil of our eye is
greater or equal to the area of the eye-ring, our eyes will collect
all the light refracted by the objective The precise location of
the eye-ring naturally depends on the separation between the
objective and the eye-piece