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.

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ZONE3 - We Last Longer

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

https://twitter.com/...s/661277249845489665
http://forum.slowtwitch.com/...ield%20aero#p5754898

I wear Giro Air Attack with visor, and my prescription glasses. Works well

+1

Also, I have a friend who wears his glasses with his Giro Selector with the visor on. It's a little tighter, but he got it to work.

Mike

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.

Casco aero helmets fit glasses under the visor.
Don't know if they are certified in the USA yet though.

Get LASIK. Just find the money and the time and get it done. Best thing I ever did.
Perfect vision all the time changes your life.