Due to my poor eyesight, and dislike of contacts, I always wear prescription sunglasses on the bike. Many of the better aero helmets seem to be using integrated visors, and I haven’t seen much data on how well they perform without the visors.
Not exactly the answer to your question but …
Depending on the shape of your glasses you may be able to wear them under the visor (should probably not be sunglasses though). On my Giro Aerohead for example I can wear my normal glasses with the visor. (Still prefer Contacts, but the option would be there). Mayby it would fog up a lot though.
I’ve got a proper set of sunglasses with inserts (Smith Pivlocks + Rx Insert) stuffed into my Bell Javelin with visor. Bonus: Extra-dark combined tint is great for desert glare.
Going to test a friend’s POC Cerebel soon, looks like it could fit a pair of glasses behind the visor too.
I wear my rx Rudy Project Rydon sunglasses under my Bell Javelin helmet without a problem. It’s a little dark, but I didn’t have any problems with fogging or visibility on a very wet day at Mont Tremblant a few days ago.
I just tried on my Giro Selector with the shield and my glasses, as I usually race in contacts. It didn’t work…There is some data out there about shield vs no shield with specific helmets. Check the twitter link and slowtwitch link below. I think the general rule is that if the helmet is designed with a shield it is probably faster with it on. But as we all know, there is no ‘fastest’ helmet for everyone…YMMV
I wear glasses under my Bell Javelin. It is tight, but it works OK. Putting it on takes a little care, but taking it off has almost no impact with the glasses. The time impact cannot be that significant in seconds, if measurable. I will probably check out the Aerohead or Bambino at some point. But that is the balance of cost versus how much time could I realistically save from my current aero helmet.