Semi round flip-up sunglasses are rated UV400 with polarized gray, amber, brownish amber & lite yellow lenses fitting onto round shape prescription glasses.
One single lens measures 52mm width x 47mm height
Total width across measures 120mm width by 47mm height
One single lens measures 54mm width x 49mm height
Total width across measures 127mm width by 49mm height
Your glasses need to be the same size or slightly smaller than the above specifications for the clip-on to fit properly.