Focusing with rz67 and glasses

I use reading glasses, 2.5, and notice when doing some still life that a lot of negs have bad focus does anyone have problems like this.I use an rz67 without my glasses it has a -1.5 diopter

The trouble using reading glasses for focusing is they are designed for 12 to 14 inches viewing distance therefore the focus screen must be that distance from you to see the screen accurately. A second pair of a higher power such as 3.5 or 4 on over the standard reading glasses improves the magnification.
For 135mm cameras I use my 1.75 reading glasses for camera operation and no glasses for focusing as the built in dioptler is adequate. For medium format I must use the built in magnifier or use higher power reading glasses. For 4x5 and larger I use a loupe.

Mamiya made a variety of diopter correction lenses for your finder.

I was able to find diopter corrections for both the waste level finder and the prism II. Works great.

As for glasses, I purchase two pairs . . . one that optimizes the right eye and one the optimizes the left eye. (At the desired distance.) Then, it's a matter of swapping out one lens for another in one of the pair. Maybe not quite as good as prescription glasses; but, a lot less expensive. I have one pair for music, one for reading, and a third for use under the darkcloth.