Hi Jazz, nice clean metals indeed. The white eyes is a tricky one to sell. The example mini that springs to mind is the GW Astropath but that has a cowl & more "magical" appearance. The standard approach seems to be very heavy shading around the eyes, perhaps with a tattoo/makeup element of design to it to draw attention to the fact that there's something special about the eyes (sell the reason that they're not normal). A tiny glaze of an unnatural colour rather than pure white might help?
My other thought is to add to the mini elsewhere to sell the special nature of the eyes. If the gun had a big telescopic sight on it'd be easier as you could put a blindfold around it to sell the fact that he doesn't need a visial aid. An embroidered insignia on shoulder of a white eyed Cyclops head?
Perhaps the simplest would be to white OSL the eye? That way it'd give good reason for the flesh tone to not be as fully highlighted as it could be taken to.
Anyway, just thoughts

Nice paintwork & I think it's obvious you're a good enough painter that you haven't just chickened out of putting in pupils, the eyes are like that on purpose - not as easy to tell on some Gallery entries
Cheers, B.