My big head is long, front to back but narrow. I usually have to get the biggest helmet I can find so it doesn't uncomfortably press on my forehead but usually ends up being loose side to side.
Now I have a large Leatt DBX 2.0. It's a cross country mountain bike helmet but I use it for all my road riding as well. It's by far the most comfortable helmet I have ever owned. I broke one in a MTB crash and replaced with the exact same model. I've never liked a helmet enough to replace it with the same thing before. If anybody local sells Leatt I would recommend checking them out if a helmet visor doesn't bother you.