Chloromyia formosa eye middle
The Chloromyia formosa is also known as the Soldier Fly. I think this one is a female given the colour of the abdomen.
This shot was taken with my reversing ring on my 14-42mm Olypmus Zoom set at 42mm. The distance between lens and fly was maybe 1cm - focus is by moving the camera! You'll see the DoF is paper-thin, haven't figured out how to expand it much as yet.
Here I caught focus on the middle of the eye showing some of the individual lenses and the hairs on the eye in detail.