PD responsibilities

[Barry Santini]

Yes Barry and if the patient moves their head up or down, their heights will be wrong. But the point of what we do is start from a position of the highest accuracy possible, to minimise errors and maximise the patient's vision for as large a part of their life as possible.
Nothing is perfect, but that doesn't stop us aiming for perfection.

If high accuracy is the goal, you’d never use a PD taken objectively with a ruler or via corneal reflection

B

[optimensch]

If high accuracy is the goal, you’d never use a PD taken objectively with a ruler or via corneal reflection

B

I guess by accuracy you mean the wearer's comfort and the visual experience of having the best possible optics in their direction of gaze (primary position for far and whatever the reading distance is) - centering the optics with their main visual axis -

I was wondering if you had a trial frame with 2 single pinhole lenses which allowed for monocular adjustment of pd - if you had a well designed target at 20 ft straight ahead of the patient - and you ask them to subjectively center the pinhole in each eye to put the target in the middle (best position) - would this be optimal.

Thoughts?

[Jason H]

A ruler has worked for centuries, PD gauge (corneal reflection) for decades. Now they're inaccurate? No sale here.

[Barry Santini]

I guess by accuracy you mean the wearer's comfort and the visual experience of having the best possible optics in their direction of gaze (primary position for far and whatever the reading distance is) - centering the optics with their main visual axis -

I was wondering if you had a trial frame with 2 single pinhole lenses which allowed for monocular adjustment of pd - if you had a well designed target at 20 ft straight ahead of the patient - and you ask them to subjectively center the pinhole in each eye to put the target in the middle (best position) - would this be optimal.

Thoughts?

Sounds goods. But I implied nothing about wearer comfort. Just accuracy of positioning

B