Polarization Vision and Its Role in Biological Signaling

Abstract

Visual pigments, the molecules in photoreceptors that initiate the process of vision, are inherently dichroic, differentially absorbing light according to its axis of polarization. Many animals have taken advantage of this property to build receptor systems capable of analyzing the polarization of incoming light, as polarized light is abundant in natural scenes (commonly being produced by scattering or reflection). Such polarization sensitivity has long been associated with behavioral tasks like orientation or navigation. However, only recently have we become aware that it can be incorporated into a high-level visual perception akin to color vision, permitting segmentation of a viewed scene into regions that differ in their polarization. By analogy to color vision, we call this capacity polarization vision. It is apparently used for tasks like those that color vision specializes in: contrast enhancement, camouflage breaking, object recognition, and signal detection and discrimination. While color is very useful in terrestrial or shallow-water environments, it is an unreliable cue deeper in water due to the spectral modification of light as it travels through water of various depths or of varying optical quality. Here, polarization vision has special utility and consequently has evolved in numerous marine species, as well as at least one terrestrial animal. In this review, we consider recent findings concerning polarization vision and its significance in biological signaling.

Navigation by light polarization in clear and turbid waters

“…Though the signalto-noise ratio is low at lower Sun elevations, high polarization sensitivity may help to overcome this limitation [16]. Hence, we expect that polarization cues, under the specific conditions mentioned above, could be used by marine animals for navigation (e.g.…”

Advanced visibility improvement based on polarization filtered images

“…Motivated by polarization sensitivity in marine animals, 3,[17][18][19][20] it has recently been shown that underwater path radiance can be compensated for 12 by analysis of polarization-filtered images. Therefore, some of the problems addressed in the current paper with regard to haze may apply underwater, or in other media.…”

Evolution of Insect Eyes: Tales of Ancient Heritage, Deconstruction, Reconstruction, Remodeling, and Recycling

“…Among them is the ability to detect the direction of the electric field component (e-vector) of linearly polarized light (see Labhart 2006 andHorváth andVarjú 2004 for recent reviews). This ability can be used for orientation (Wehner 1992;von Frisch 1967), the detection of water surfaces (Horvath and Varju 1997;Schwind 1991), and in communication (Cronin et al 2003;Marshall et al 1999). A specialized region for polarized vision exists in the dorsal rim area of most compound eyes.…”