Your horse literally doesn’t see the world the way you do.
I don’t mean they interpret things differently (though, of course, they do), but their vision is so different than our own that they are actually seeing things differently than we are.
I think it’s a common occurrence that we assign some sort of intentional misbehaviour in a situation where the horse was actually not able to see well enough to do what was asked of them.
Horse’s depth perception works entirely different than ours, and still isn’t very good. They rely 100% on their ability to move their head and neck up and down to determine depth – how many times do we restrict the movement of their head and neck while trying to encourage them forward to step onto an unfamiliar surface?
Horse’s colour vision is very different than ours. Red, for example, blends into green for them, so the red pole against the green grass that we can see so clearly, they might not see at all.
Horse’s pupils adjust to changes in light very slowly. If they come from bright outdoor light into a dim indoor arena, it could be 45 minutes before their eyes adjust well enough to really be able to see in that environment.
Horses also, being prey animals, notice small changes in their environment that we (as predators) do not. It’s likely that when you’re telling your horse they’re spooking “at nothing” that their vision has shown them something that has changed, even though we don’t perceive it.
Give your horse the benefit of the doubt – they’re not trying to ruin your day, and they might just see something entirely different than what you’re looking at.
For more about how horses see and other ways to improve your communication with your horses, download my Understanding Your Miniature Horse ebook!