Bifocal focal distance

I'm getting to the age where I need bifocals. I have one pair I got a few years back, which absolutely drives me nuts. The focal distance of the reading portion is about 13 inches. I guess this is OK for 30 seconds scanning a menu, but I find it WAY to close for reading a book for several hours at a time. My arms get tired, or alternately, my back gets sore from bending over to get close enough for the book in my lap to be in focus. I would like the distance to be 20 to 22 inches. On my last optometry appointment, I asked the doctor about this. Her response was basically that the focal distance is set by the machine (the length of the rod holding the card which is used up close for this measurement) and could not be changed. How absurd. Short of bringing in a 22" dowel so this person who was too lazy to bother helping me can put her little card out at the distance *I* want, is there any way to get the lower lens to focus at 20 inches or thereabouts? Honestly, this 13 inch focal distance is good only for holding the hymnal in front of your face at the church choir.

And I don't want trifocals, or progressives. I just want regular bifocals with the reading lens set at a focal distance of 22 inches. I see no technical reason why this can't be achieved.

Any advice appreciated.

Dan

 

The minimum bifocal power you can get with a st-28 (lined bifocal) is +0.75, some labs can only do a +1.00. Unless you need less than that to get you to your desired focal length your doctor should be able to write the prescription for anything she wants. She just has to measure how much bifocal power you need at that distance which can either be done behind the phoropter and the near card set to your distance or she can hold trial lenses over your current glasses and see which power you like best.