Up to add 1.50, short or long corridor?

[MIOPE]

Which multifocal type you prefere on patients with add 1.50 and lower add. On patients with add 1.50 or lower there is enought acomodation left to almost be able to see from far to near with a bifocal. On a multifocal, the patient can almost use any part of the corridor to see at intermediate distance because the accomodation left will do focus.
If this is true, then why they make low add long corridor multifocals? Isn't the far and near portion of the lens too far away on a long corridor multifocal. Does patients complain about having to raise the head to go from far to near?

[Robert Martellaro]

Which multifocal type you prefere on patients with add 1.50 and lower add. On patients with add 1.50 or lower there is enought acomodation left to almost be able to see from far to near with a bifocal. On a multifocal, the patient can almost use any part of the corridor to see at intermediate distance because the accomodation left will do focus.

Most don't even need to look through any part of the corridor- the distance Rx is good enough from infinity to as close as about 65cm.

If this is true, then why they make low add long corridor multifocals?

Smoother, less dynamic, less distance peripheral blur- all important design factors for easier to adaptation, especially for first-timers.

Isn't the far and near portion of the lens too far away on a long corridor multifocal.

Probably. It's a delicate balance between adaptability and functionality.

Does patients complain about having to raise the head to go from far to near?

Probably not, depending on the distance Rx, add power, pupil diameter, lighting conditions, optimal positioning (fitting point center pupil) etc. Most will have a somewhat shallow reading depth out of habit, which means they'll only get 75% to 85% of the prescribed near power, usually not enough loss to trigger symptoms and/or complaints (a completely different story for more advanced presbyopes though). If they are symptomatic at near, the best course of action is to shorten the corridor somewhat, and not bump the add power!

[MIOPE]

Robert::
Great concepts you just express.
Any idea of which short corridor could be the best por first timers. We use Small fit, Consice and Navigator short but not sure they could completly replace the long corridor on lower adds. Any way, i will run my test.
Actually, Why keep a stock of low add on long corridor progressive if a short one is better?

[Robert Martellaro]

Robert::
Great concepts you just express.
Any idea of which short corridor could be the best por first timers. We use Small fit, Consice and Navigator short but not sure they could completly replace the long corridor on lower adds. Any way, i will run my test.
Actually, Why keep a stock of low add on long corridor progressive if a short one is better?

I'm saying that for emerging presbyopes, it's probably best to start with a very soft, moderate to long corridor PAL. Chances of rejection increase with the shorties. I'd recommend SV readers if there's no distance Rx. An occasional blended or segmented multifocal rounds out the options for non-CL wearers.

I like tests. You'll need a test subject(s), preferably a staff member, friend, and family member. Use the same frame and lens position for each design. You can swap out lenses for medium to long term evaluation, but I like to have two identical frames available, allowing the subject to make an immediate, side-by-side evaluation. Most labs will help out with the costs if you share the data.

[Michael Walach]

I highly recommend any individually optimized short corridor design. Real time design individually optimized ray tracing corrected lenses will have the least amount of oblique axis astigmatism even in the blend zone areas of the lens and short corridor design will give your patients the best viewing ergonomics. Try some of the I.O.T. designs, you can't go wrong.