pupil

(noun)

The hole in the middle of the iris of the eye, through which light passes to be focused on the retina.

Related Terms

Examples of pupil in the following topics:

  • Resolution of the Human Eye

    • As soon as the eye moves, it re-adjusts its exposure, both chemically and geometrically, by adjusting the iris (which regulates the size of the pupil).
    • The pupil of the human eye is its aperture.
    • Refraction in the cornea causes the effective aperture (the entrance pupil) to differ slightly from the physical pupil diameter.
    • The entrance pupil is typically about 4 mm in diameter, although it can range from 2 mm (f/8.3) in a brightly lit place to 8 mm (f/2.1) in the dark.

  • The Human Eye

    • In the middle of the iris is the pupil, the black dot that changes size.
    • The fundus is on the opposite of the pupil, but inside the eye and can not be seen without special instruments.
    • All of these are connected by the pupil.
    • Whenever the eye moves, even just a little, it automatically readjusts the exposure by adjusting the iris, which regulates the size of the pupil.
    • The pupil serves this function, and the iris is the aperture stop.

  • Nearsightedness, Farsidedness, and Vision Correction

    • In the middle of the iris is the pupil, which is the black dot that changes size.
    • The fundus is on the opposite of the pupil, but inside the eye and cannot be seen without special instruments.

  • The Rayleigh Criterion

    • This same effect happens when light passes through our pupils, and this is why the human eye has limited acuity.