My understanding is human lens is a filter - removes ultraviolet. Early replacements didn't filter, some old folks could see colors the rest of us don't know about!

Allegedly, Monet painted with more blue colors after his cataract surgery, though it's not a sure thing: http://www.skepticalartist.com/2013/06/25/claude-monet-and-u...

Mantis shrimp can see light polarization as well. They have amazing vision range.

Humans can, too, though not very well. Stare at a bright white LCD—you should see orthogonal double-fan shapes, one bluish, one yellowish.

I personally see it more readily from red LED digits on my alarm clock at night. IDK if it's generally better conditions or biological difference.

LEDs don't produce polarized light. You might be seeing the matrix scanning.

Don't know why I said LED. Alarm clocks are almost never LED. It's a backlit LCD.

They can see 6 different types of polarization though.

What do you mean by early replacements?

Cataract surgery replaces the lense with an artificial one.

Ah, thanks. I'm surprised I haven't heard of body modders getting that done so they can see UV, that sounds like a neat superpower akin to people who get magnets embedded in their fingers. Going to research risks now..

I'm going to guess the retina doesn't hold up to UV exposure too well. Seems very likely.

You would be right in the case of UVA light [1]. Though it's interesting that we have photoreceptors for UV light in the first place.

1. https://www.ncbi.nlm.nih.gov/pubmed/21646980

There are some substances that can put you there (at least in mindset) for some period of time. Noticing the beauty of a color you have seen thousands of times is an interesting thing.

I guess you could have cameras that pick up the extra colours linked to something like a Microsoft hololens and displayed somehow like a shimmer for UV say.