"The eyes of men (AND women) are not designed to distinguish between different types of polarization, contrary to insects, cephalopods, many amphibians, fish, and other animals, for which nature possesses a different class of "colors" (but even common colors do not mean the same to everyone). However, a small quirk in the structure of the human eye gives us (by accident) the ability to tell apart different states of polarization. Thanks to this small aberration or "defect" of the eye we are not completely polarization-blind." - xero from Bookmarklet