Clamp on lens with magnification

My ten year old Decots just broke and the model is discontinued.  I need to buy a whole new frame now but before I get the lenses I have a question.  I would normally get the right with my chosen diopter and nothing in the left.  If I wanted to get both lenses with zero magnification and [b]clamp on[/b] a lens with my diopter over the right, does someone make such a piece of hardware that is available with different diopters?  If so and you've used it/still use it, is there any degradation in sharpness since the magnified lens is now an additional 5mm or so away from your eye?  I'm curious about this also since it would permit me to swap in different shades more easily since the shaded lenses will all be unmagnified (they're cheaper this way as well).
Thanks,

ShootingSight makes clamp on lenses.  These are polycarbonate eyeglass lenses with AR coating.

Flip lenses