Properly adjusting bifocals, trifocals, and progressive lenses is often an easy fix for many confusing patient vision problems.
Bifocals should be fitted so the top line of the near segment rests at the lower eyelid margin.
Trifocals should sit a little higher, with the top line of the intermediate segment aligned with the lower pupillary margin.
The seg height of a progressive lens is based off of the center of the pupil, but patients sometimes don’t wear their glasses the same way they were measured. Listen to these patient’s complaints. If they have to tilt their head back to read, the lenses should be adjusted to sit higher on their face. If their distance vision is compromised, the frame may need to sit lower on their face.