Working Distance question

[tx11]

Lets say a Pt normally has an add power of +2.00 for a working distance of 16" but wants his working distance to be at 20" instead of 16" and he is wearining a PAL. (you have no idea where on his lenses he is normally looking...full strength of add power or just above that or in the intermediate) What's YOUR best practice for determining add power for working distances farther away than the norm in a PAL wearer? okay go....

[Robert Martellaro]

Trial framing.

Use a lens design that places the correct power in a way that minimizes posturing and maximizes acuity and FOV. Best results usually require a separate pair of task eyeglass, but if we're just talking about a tall person with long arms reading a book or tablet, just cut the add if it was set for 40cm (15.75"). The smallest text might become problematic so make sure your client understands how this plays out.

[tx11]

Thanks Robert. That's we ended up doing ( sort of like it was a regular FT28). I just didn't know if there were special considerations that other opticians might take into account for PALs. Since there is a progression in power, the PT doesn't have the line to "tell" him exactly where to look for the new weaker add and longer working distance.

[Robert Martellaro]

Thanks Robert. That's we ended up doing ( sort of like it was a regular FT28). I just didn't know if there were special considerations that other opticians might take into account for PALs. Since there is a progression in power, the PT doesn't have the line to "tell" him exactly where to look for the new weaker add and longer working distance.

Your welcome. I have them hold a reduced snellen chart for 16" held at 16", and check if a chin lift improves the vision. If it does, they're only getting 80% to 90% of the add. If posturing doesn't change the vision, they're in the zone (near).