Eye: Structure and Optics

The human eye is a simple, but extremely robust, optical instrument. It produces images of the visual world onto the retina with a quality that [Page 414]matches or exceeds the resolution of the neural circuitry. The eye is composed of only two positive lenses, the cornea and the crystalline lens, that produce real images of the world on the retina, initiating the visual process. Traditionally, the eye has been regarded as an equivalent of a camera, with the ocular optics acting as the lens and the retina as the film (or the sensor). Compared with artificial optical systems, often formed by many lenses to improve image quality, the eye is simple, but well adapted to the requirements of the visual system. Lenses form images of ...