The backbone of the book consists of the 16 chapters on eye anatomy and physiology, but these are leavened by a variety of devices to inform us of the eye's evolution, development and intellectual ...

Difficult, but not impossible. Scientists have come up with scenarios through which the first eye-like structure, a light-sensitive pigmented spot on the skin, could have gone through changes and ...

The amount of light entering the eye is controlled by a reflex action. The size of the pupil changes in response to bright or dim light. This is controlled by the muscles of the iris.