The silicon retina.

1 The retina is a thin sheet of neural tissue that partially lines the orb of the eye. This tiny outpost of the central nervous system is responsible for collecting all the visual information that reaches the brain. Signals from the retina must carry reliable information about properties of objects in the world over many orders of magnitude of illumination. Furthermore, these signals are generated by transducers whose characteristics are innately mismatched and must be continuously self-calibrated. Some of the mechanisms by which the retina achieves this feat are embodied in a two-dimensional CMOS chip, the silicon retina.