There is some current web-wisdom going around that the human eye is unable to see polarised light – this is about as accurate as the observations of Mars as big as the full Moon.
With nothing better to do whilst sunbathing on a beach on a Greek island I practically put it to the test whether I could see regions of polarised light or not with the naked eye.
If you’ve done some basic optics you will know that if you look at the regions 90 degrees horizontally to the right and the left of the Sun, then these regions should be quite highly polarised. Why? Because any dust (dielectric) in these regions will be receiving light from the Sun at a glancing (shallow) angle and the light that is reflected from the dielectric towards your eye will be polarised.
I took a look at these two regions with the naked eye and saw nothing unusual. I then picked up my Polaroid sunglasses and rotated them in front of my eye over these regions. A bright patch appeared and disappeared depending on the orientation of the sunglasses, this was clearly a region emitting polarised light. Now knowing precisely where to look I checked it out with the naked eye and could clearly see two mauve/purple regions precisely where the polarised light was coming from. So the eye IS able to detect regions that are producing polarised light. Mine can anyway 🙂
