Based on the wording of your post, I just thought I'd point something out...
When you look through a rifle scope while wearing glasses you tend to look through the upper and sometimes inner corner of the lens... and, depending on the rifles LOP and your body position, with the glasses lens at a relative angle to the scopes focal centerline as well.
If you're looking through scopes that are not mounted to a rifle, you tend to look through the corrective lens element.. and head on. You also may be looking through a scope without regard to a mounted scopes eye relief.
Most scopes have diopter adjustments. The range will vary from maker to maker and from a specific scope type to another. Some have only a +1/-1 range, while others have a +3/-3 range... and variation anywhere between.
If you've taken all this into consideration already, I apologize for stating the obvious. If not... then you have these variables to consider.
Shoulder Drive Nicholson Club