Murray wrote: ..... My original mistake was going to my regular optometrist who frankly had no idea about spectacle manufacturer...... I guess I should modify my original comment - make sure that the people who are providing your prescription cycling glasses understand the intended usage and the construction of the frames.
Yes, when I first went to my optometrist she had never seen a pair of cycling glasses before and was dubious about getting the right prescription into a curved lens. However, to her credit she took the time to investigate the issue, did some research and came up with 3 or 4 options for me to consider. She was then able to measure my eyes for all the extra data needed to write a prescription for curved lens and to identify the right points for all the different focal lengths within the lens prior to ordering. After delivery, she was careful to ensure that they were adjusted & fitted correctly.
So, what Murray & I are saying is that you will get a better result if you find an optometrist who takes an interest in your cycling needs and values you as a customer rather than just buying a pair online and/or from a bike shop. I understand this may require a bit of searching around until you find an interested & helpful optometrist. They do exist.
If your needs are less complex and you don't need to see an optometrist for multi-focals there are cycling glasses with a small bi-focal strip at the bottom that sell for less than $50. These give you long distance forward vision through the top and a small close vision (magnified) strip at the bottom - designed so that you can read the trip computer as you ride and/or your phone/Garmin when you're stopped. Ideal for riders who can mainly see OK but just need a little help for the very small close stuff.