I highly encourage anyone who had birds crash on their windows to install white dot stickers. I installed some last spring on my windows and not a single bird crashed on them since.
At first they look a bit odd, but after a week they were almost invisible, turns out the brain is really good at hiding things we don't care to see. They are a bit of a pain to install but it is well worth the effort.
Worth mentioning there are pricier but even more invisible, similar idea solutions. I've got stickers I put on my house and have suggested to clients that are translucent in the visible spectrum but strongly reflect UV. Lots of birds (and in particular songbirds, these are on rural residential buildings with no more than 3 stories so raptors aren't going into them) have receptors for ultraviolet, so to them the stickers look opaque glowing white. They're effective and may be more aesthetic, though again more expensive (they need to be replaced every 6-9 months, the chemical that reflects UV breaks down). Another approach I've used is a sticker that simulates a golden spider web. While not translucent, the thin web look is very subtle, but apparently a lot of birds have evolved to be very hard wired to avoid flying through heavy spider webs so it triggers an avoidance response well.
Finally, there are bug screens that have gotten very subtle too (high density thin weave with low visibility materials used in their construction). As well as reducing external reflection, those will just plain act as a softer shock absorber if a bird runs into one. And of course keep out insects, so doing their job anyway.
I'll add that I still do have (far fewer) bird hits once in awhile, but the big change seems to be outcome. Before a lot of birds died. Afterwards what seems to happen is the hits still see it at the last moment, and the hits have 99% turned into bellyflops. Not fun for the bird no doubt, but it also isn't lethal, they just fly away. Bird death in my experience is generally caused by broken necks, they fly in head first and their neck snaps and that's it. So even if they swerve as the very last moment, it's still a huge boost in survivability. On a big building it might help to have some nets out of sight below windows though so that birds which are temporarily stunned don't fall all the way to the ground.
The UV stickers sound interesting, but is there a (human-)visual indication that they've stopped working? If not, there'll be a whole lot of useless dots on windows, making owners feel better but not actually helping anything.
Unless you have a UV camera then no, there is no indication to humans [0]. Though as sibling said, if nothing else you'd have the obvious direct grim evidence if they had failed. But at the same time I've not found it a concern in practice, there's plenty of stuff in a household that simply needs to be replaced/renewed on an annual or semi-annual basis with no particular indicator before failure. Just part of building maintenance. I set an annual calendar notification and roll it into spring/fall cleanup lists along with things like gutter cleaning. They don't just fail at wildly varying rates, it's a straight forward curve of breakdown so when it says "replace these every 6 months" one can just do that.
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0: FWIW you can get basic simple monochrome UV-USB 1080p cameras (350-380nm range or so, to get down to 300nm requires much more expensive lenses) to play with for <$250 new, similar to basic low res FLIRs. They can be interesting looks at the world, you can see everything from sunscreen applications to UV patterns on some flowers.
A few years ago, my wife was taking photos of spectral lines of a mercury lamp with our normal camera and she noticed an additional line in the photo. It was an UV line that was visible by the camera but not by the eye.
[IIRC a Cannon camera, not very expensive or fancy. It was very good taking photos of dark rooms during birthdays.]
Also for deer. Deer are idiots, the males even more so during the rut. They will see similarly-sized deer in any vertical glass surface (their own reflection) and charge the window antlers-first. They break through the glass and now you have a deer running around inside your house or school. A few stickers won't stop them from seeing their reflection, but it will put an "object" between them and thereby stop the charge. I've even seen this in car windows. Tall deer (elk) are so dumb that they will repeatedly charge the tiny elk reflected in a car window. They aren't attacking the car but the other elk they think is inside. I'm surprised they all don't drown every time they see rival elk inside a calm lake.
I had a robin nest in my backyard close to my French doors. Every day one of them would pass by the doors, see their reflection and then attack it. Apparently they like to keep out competitors when they're nesting. They would at it for hours until I obscured the lower half with some potted plants.
My partner has a very white bicycle helmet and bugs are often flying into it for the same reason I think. Mines darker and it almost never happens other than the occasional and expected collision.
I get a lot of birds in my yard and decorated the windows with translucent UV stickers. Now every sunset I get to see a stained glass dragon on my wood floors. Highly recommend.
I don’t like stickers on my windows, ruins the aesthetic. Instead we should have some kind of spray that transmits a wavelength of light only birds could see but is invisible to humans.
At first they look a bit odd, but after a week they were almost invisible, turns out the brain is really good at hiding things we don't care to see. They are a bit of a pain to install but it is well worth the effort.