For whatever MY opinion is worth...
Over the last few years I've driven Offrs, Sr NCO's, and other VIP's around. When talking to them directly (while not driving), I take my glasses off. When driving, they be on.
My glasses are Oakley's, black frames, black lenses, and nope, you can't see my eyes in them. Never met anyone higher yet (an RSM?) that INSISTED that my eyes be visible but NO ONE has once complained, esp when the glasses are off when appropriate. Always thought that if'n y'all jes' git "quiet-coloured" glasses and wear them when necessary, never have a problem. Pink?!? Dark pink, MAYBE... ;-)
Of course, even in the regs, the measly $26 glasses allowance can be useless. I have a big melon so I needed special frames; only Oakley made a frame big enough. Plus I ordered full UV protection (to prevent cataracts) and polarized lenses (greatly reduce eyestrain) for a total cost of over $500. Had to take it on the chin myself, but worth it.
Of course the problem is what happens on a bright sunny day when in the field, doing something tactical? The goggles still aren't avail to support types (so I've been told in Wx) so if I damage my shades in the field, it's $500 buckaroonies down the drain.
I've tried clipons over my regular glasses, but they're just too darn heavy. With a sweaty face, they just slide down. I imagine this is everyone that wears glasses in the field? And unfortunately you can't wear those black tie things around the back of your head to hold your glasses on, not that you'd see it anyway with the helmet on.
So for now, it's me and my $500 buck Oakleys. Should get them insured... :