The hot sun on my car bonnet seemed to attract half a dozen horseflies (Tabanus bromius). I had a bit of fun taking some close up shots. Yes it has green eyes with a red stripe – follow of the sequence of photos.
A Dartmoor blog
The views and photographs of Adrian Colston
Amazing eyes… 😁
I suspect that the eyes are not themselves coloured green, but that the complex pattern of the compound eye forms a diffraction grating, giving a green coloured interference pattern – it is iridescence, like some of the patterns on butterfly wings. I find that a wonderful thing.