It's why deer-vehicle crashes are so common. Deer are pretty fast, and don't have any reason to stand in a road (there's nothing for them to graze, after all). But if they're crossing the road when you come along and your headlights suddenly blind their dilated eyes...
(By the way, their eyes are more like a cats, with pupils that can dilate far wider than a humans, so imagine a cop suddenly aiming a spotlight at you when it's pitch black - and then make it several times worse...)
I hit about a half dozen of them when I was younger.
Freezing in front of the lights is a big issue, but a bigger one is that they flip out and do weird stuff based on the sight and sound of the car at twilight. I had one jump into and break the driver side window of my car on one occasion.
(By the way, their eyes are more like a cats, with pupils that can dilate far wider than a humans, so imagine a cop suddenly aiming a spotlight at you when it's pitch black - and then make it several times worse...)