Based on people I’ve spoken to post-cataract operation with UV-transparent lenses (which are becoming more uncommon) it appears as blue or purple patterns they couldn’t see before. Very anecdotal.
Most bird species have four types of cones rather than the three seen in humans, in other words, they’re pretty much all tetrachromats. And birds definitely qualify as “animals”. The mantis shrimp with its astounding 12 different visual pigments has also been mentioned.
How does someone being colorblind affect the color balance of artwork, etc.? For a tetrachromat the normal human is essentially colorblind. Artwork produced by such a person is going to look normal to the average human, but tetrachromats are probably going to be VERY picky about color selection and mixing.
Yep. Your retina is basically highly modified skin tissue, and we all know what extended exposure to UV radiation can do to skin, right? Melanoma can occur in the retina, which is a skin cancer linked to UV exposure.
If you get UV-transparent lenses I highly recommend you wear UV blocking sunglasses outside most of the time.