Recently fitted a pair of Hoya FD1.6 short corridor design. When patient put on his new prescription, he complained that the distance vision is not clear when looking straight ahead. no problem with near vision. he mentioned that distance vision is clearer if he tilts his head down.

His old lens is essilor comfort 1.6. Rx is almost if not exactly the same for the distance with an increase in near add.

PD is accurate. prescription on the FD is also same as prescribed. I do not think the Rx is inaccurate as he said it;s clear when I put the Rx into the trial frame.

So what could be the problem?

So far I would say I am not quite happy with FD as I get s few similar problems too with this lens in the past.