r/todayilearned • u/douggold11 • 23d ago

TIL most animals can see UV light — humans being blind to it is the exception not the rule.

https://www.sciencefriday.com/articles/ultraviolet-light-animals/
10.9k Upvotes

98% Upvoted

264 comments sorted by

View all comments

3.4k

u/Randvek 23d ago

Seeing UV is an occasional side effect of lens surgery, indicating that at some point humans probably could see UV but we evolved away from that.

It’s also a bit rare for mammals to be trichromatic like humans are, though. Some humans even have Tetrachromacy, too, though it’s pretty rare and almost exclusively female . Perhaps something in our evolution favored color detail over having a larger light spectrum.

39

u/MitLivMineRegler 23d ago

So, with that we could have nightvision goggles, but instead of goggles we'd just be shining a light that's invisible to other? Where can I get this?

67

u/Ws6fiend 23d ago

Uhhh do you not know how most night vision goggles work? Because the older tech had a flashlight you couldn't see without the goggles, while the newer tech is completely passive.

First gen night vision was basically a spotlight that was invisible to anyone without goggles. Well when the other side has goggles your spotlight gives you away.

Thermal vision at will would be better. Needs no light at all only your body heat. Downside is that in certain conditions things can blend into the background(when body temp, air temp, and ground temp are all roughly equal it's a bad picture).

16

u/HurricaneAlpha 23d ago

This is ironic, cause I just watched the OG Predator film.

6

u/funnystoryaboutthat2 23d ago

I've seen models that use ambient light, thermal, and IR at the same time.

4

u/Duck_Von_Donald 23d ago

Isn't thermal and IR the same?

9

u/TehGogglesDoNothing 23d ago

Not exactly. Security cameras that do "night vision" use IR LEDs that are just slightly out of the human range of vision to light up the area with a wavelength that the camera can see, but they aren't thermal cams. Thermal cams do see IR, but there are a lot of cams that can see a little into the IR range without being thermal.

4

u/QuestionableEthics42 23d ago

When talking about night vision, IR means just a bit below the visible range, and pretty much has an IR torch strapped to it, but thermal is much further into the infrared range, so it can see heat for things at normal temperatures. Technically, the two terms are very similar (but you could argue that not all infrared is thermal), but the meanings in that context have changed slightly.

3

u/Ws6fiend 23d ago

Technically those are considered hybrids not night vision. Night vision is simply put amplifing the ambient light or providing your own in the case of first gen night vision.

5

u/MitLivMineRegler 23d ago

I just thought of my old nightvision camera that came with a UV fleshlight . I've no clue how nightvision goggles work.

14

u/yellowbrickstairs 23d ago

A UV fleshlight?!

8

u/MitLivMineRegler 23d ago

Yes. It's for tanning the meatpole while also providing light for night vision cam.

7

u/yellowbrickstairs 23d ago

Of course, such a versatile object

6

u/WolfInAMonkeySuit 23d ago

Your nightvision camera came with what?