A.1 The Physiology of Vision

An image does not really exist if we can’t see it. We’re able to see things thanks to the complex and precise organ known as the eye. Our eyes produce the images we see by interpreting a small range of the electromagnetic spectrum known as the visible spectrum.

How the Human Eye Works

Figure A-1 is a diagram of the human eye, showing its main components. Light enters the eye through the pupil and is focused by the crystalline lens, and an image is formed in the back of the eye on the retina. The lens is flexible, and small muscles around it allow it to deform to change its focal length. This allows us to focus on objects at various distances. The diameter of the pupil is also variable, which provides a way to regulate ...

Get The Book of GIMP now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.