These two are small, so it’s no surprise that I only have one example of images of them, though I think I might have seen another last year when I didn’t have the camera in hand. This is a type of Syrphidae, or the hover fly family, known only as Orthonevra nitida, and the eye pattern is apparently specific to the eastern half of the continent.
Why do the eyes look like this? I have found no explanation, and even idle uneducated speculation (well, my own, anyway,) hasn’t provided a clue. Given the other markings and even the wing veins, I’d be inclined to say it was camouflage, but likely not from blending in, since hover flies routinely alight on flowers that look nothing at all like this. However, it’s possible that they resemble something like caterpillar feces and thus avoid predation through germophobia. Then again, if you refer to this image, it’s easy to believe they do it on purpose just to freak out the stoned predators.
And while the short depth-of-field makes it far less obvious, this is actually a mating pair, though which one is facing us, I can’t say. But notice that one simple eye, right in the middle, staring right into our souls…