Re: Progressive Lens Choices

It's probably safe to ignore the VI (vertical imbalance) with this type of Rx.
However, if you wear multifocals, and you experience fatigue after a long
stretch of close work, VI might be the culprit.

Could VI be one of those things taken into account by the computer
programs that calculate "individualized" lens surfaces?

In other words, better quality lenses do not make up for bad opticianry.

If I lived within an hour of Wauwatosa, I'd beat a path to your shop.
I do know of a "Guild" optician in my area. Does that designation
count for something extra these days?

Depends on the material choice, service, and the type of aberrations and
distortion that needs to be minimized. However, looking at your situation; ie,
changing from SV to a +2.00 Add PAL (progressive addition lens), I'd probably
give the nod to the Hoya lens due to how well it reduces skew distortion,
amongst other factors. The less expensive iD Lifestyle would be very close in
performance, and comes in Trivex. Both come in two corridor lengths- the longer
one (14mm) will have the best distance vision, and will still be ok for close
tasks.

I checked out Hoya's web-posted information on the iD Lifestyle, and
it looks like an excellent choice on multiple criteria: design,
materials, coatings. (It seems, however, that the longer corrider
version is 18mm vs. the 14mm you cited.) I also received a reasonable
price quote from the aforementioned Guild optician, which would put a
second pair of the same lenses adjusted for office use well within
range (pun not intended).

I was impressed by Hoya's (realistic?) illustration of reduced swim
effect on stairs. I'm surprised they don't tout it as a safety
issue. But I wonder if anything in particular is attributable to the
front-back split of the reading correction. Couldn't a ray-tracing
program compute a back-only surface with identical performance?

You still might need an additional pair of single vision for music- use a +1.50
or +1.75 for the Add, or if you need distance capability, then a high set ST35
(a wider than normal lined bifocal). However, you might find the computer
glasses adequate for the *** music. Make sure that the optometrist or optician
shows you the quality of vision at both 20" and 30", using a variety of power
combinations.

I've been thinking about some of the peculiarities of the piano
application. When marking music, it helps to see clearly at 12"
inches. When reading music, it helps to see clearly at 20" for an
upright, 30" for a grand. When positioning fingers on the keyboard,
freedom from spatial distortion matters, so playing without refraction
might be best. When playing in an ensemble, seeing other people's
facial expressions at 6 to 12 feet can be important. Perhaps no
single design can meet all these requirements optimally at once?

Hope this helps,
Robert Martellaro

It does. I've leared a lot from your posts, here and on OptiBoard.

"Science is a way of trying not to fool yourself."
- Richard Feynman

Sometimes the effort is actually made in earnest.
/David
.