Biology provides us with fascinating examples of intelligent, low power, and highly efficient sensory systems. With the advances in CMOS technology, it has become feasible to build microelectronic systems that mimic some of the key features found in biology. This talk will focus on CMOS vision sensors for polarization imaging. We will review briefly the concepts of polarization and how it is used by various species in nature to enhance their vision or to aid with navigation and communication. Inspired by the biology we have explored polarization for a variety of applications to detect features that are hard to see or even invisible to the human eye. More recent results from the literature including the use of polarization imaging for disease detection will be reviewed. Motivated by the potential advantages of polarization imaging, we have developed a CMOS imager that combines the pixel array with micropolarizers and on-chip processing. Details of the design and polarizer optimization will be described.