Liquid Crystals, the Visual System and Polarization Sensitivity 

We have examined the vertebrate visual system from a liquid crystalline perspective, with the aim of understanding the mechanisms responsible for polarization vision in vertebrates. Using a technique called micro-spectrophotometry (MSP), we show that the different types of light-sensitive cells in the retina absorb polarized light differently. Based on these measured geometries of absorbance, analytic solutions to Maxwell's equations using a 44 matrix technique demonstrate the possibility of intrinsic linear dichroism under axial illumination in those photoreceptors sensitive to polarized light. This provides a new mechanism for axial polarization sensitivity in vertebrate photoreceptors.