I too have the Panoptixs bifocals transition lens with a grey tint No need to change glasses when going in and out of places or in and out of the sun. Great sun glasses and great reading and seeing glasses. Also they have the removable foam insert. One of the best purchases I have made.
I have 2 pairs that I use one is a pair of the old plastic framed RayBans, I use these about 90% of the time and when it's real windy or cold I have a pair of WileyX's with the foam seals, both work very well and both can take a real big scrip like I have.
Try WalMart Sunglasses. They fit over, and enclose on the sides. I use the small ones (Sport Model) and they look pretty good. They are very functional. Sorry no pix. Camera on the fritz. You'll be surprised how effective these are. $18.95 pr. I always carry at least two pair.
Get you an EXO-100 helmet with internal half visor. Comes with light tint but they sell all kinds. Put on a dark during the day with your glasses, and the clear at night with your glasses. The visor changes out super easy. Works for me, or you can keep buying winshields.
I wear prescription sunglasses with high impact lenses from Wiley-X. They are great glasses. I took a rock to the left lense on I-95 that hit hard enough to move my head. All it did to the glasses was make a very tiny little chip, not much more than a speck. As for windshield, my SG has an 8" Clearview. The combination works great for me.
Wife had the same problem. She has prescription glasses but they weren't sun glasses. We went to wallmart on their little spin stand and found some sun glasses that fit over glasses. They look pretty good. Obviously a bit bigger than she would normally wear but not enough to notice and they are fairly stylish as well. She loves them and even wears them when not riding.
I just use an Oakley goggle that fits completely over my glasses. Has clear and dark lenses for day/night use. Comfortable, easy, and cheap. About ~$35.