Rob, up to you to decide the sphere value for a good foresight. If you don't have astig. or prism problems, try out some ready readers to get what will usually be a +ve value. If you have a negative prescription you'll have to estimate from the "near" or "reading" value. If you have astig. you'll have to estimate the sphere from the near value on your prescription. A pistol shooting lens will be weaker than reading, stronger than distance.
Until my astig. became noticeable (and before the Knobloch frames came along at a giveaway price!) I used a ready reader frame with a lens made by an internet Co. like reglaze.
Last edited by derekm; 30-01-2019 at 04:53 PM.
Walther CP-2 Match, FAS 604 & Tau 7 target pistols, Smith & Wesson 6" & 4" co2 pistol, Crosman 1377,
Baikal IZH 53 pistol, Gamo CFX Royal,177, Umarex SA-10 CO2 pistol.