ABSTRACT
There are several very close resemblances between the mammalian eye and a photographic camera. The essential parts of a camera are a sensitive plate to receive the image of some object being photographed, and a lens to form that image. The camera, like all other optical instruments, is blackened inside. The extreme minuteness of the image in the eye is a fact which very few people realize. In the mammalian eye this bodily movement of the lens cannot take place on account of the way in which the lens is suspended in the eye. There is one more resemblance between the eye and the camera with which we may close this study. The camera has a number of metal discs called “stops” with circular holes in them. Now the eye has an exactly similar apparatus in the circular iris with its central circular aperture the pupil.
