Something I found that really helps with glare is a strip of black Gorilla tape about 1.25" wide across the top of the visor. It seems to cut down the glare when riding into low angled sunlight but doesn't hinder my field of vision.
My C3 is tight for wearing sunglasses....the built in tinted visor is "okay" but not as optically correct.
Still working on a set of sunglasses that fit comfortably in the C3.
I prefer sunglasses as you can get better optics and clean them more completely.
My RayBan "shields" work wonderfully for my convertable helmet in Australia. they are pretty much full eye cover and very relaxing in bright sun. It was dumb luck they work inside the helmet I use for Australia....not even close to fitting on the Canadian helmets.
Be careful with anything polarized as it can get "interesting" if you flip your clear shield down.
On my old helmet AFX-55 ( I wear the bottom config )
that I used on the latest trip I do have a metallic full shield in gold that I bought as a bit of a lark and on a bright sunny day it is the best of all.
While it's gold on the outside the actual vision is colour correct and just dimmed down ...eyes relax instantly but it does make you look like a spaceman.
Value for money on the AFX-55 is superb and the optical clarity and very wide field of view was a treat. Visors reasonably priced too.
The Schuberth C3 I bought used for $300 cdn and it's my go to for cooler weather and it simply does not fog.
It's pretty warm tho, visors pricey and certainly not worth the money new in my view.