If you ordered your old glasses through Decot; they will have all needed information on file. I recently ordered new prescription lenses from them and they had all the pertinent information on the glasses that I ordered from them, (approximately 4 years ago), to include the type of bifocals that I have. Ed
I had different results with prescription lenses for my Hy-Wyds. My eye doctor had to adjust the notches of my last pair with a Dremel tool. It looked like there are small differences from one frame to the next, and the thickness of the lenses at the edges makes a difference. It worked out OK, but the lenses as delivered by the lab (not Decot) just plain didn't fit the frames.
I just ordered another pair in another color, and this time, we agreed I should give him the frames for a week so they could be fitted correctly. They're still good shooting glasses.