On Thu, 7 Feb 2008 06:59:21 -0800 (PST), DAB <
David.Boulifard@att.net>wrote:
Quote
I'd like to solicit advice about choosing progressive lenses for two
pairs of eyeglasses, devoted respectively to generalized and
occupational uses.
I am 51 years old, with no history of eye diseases or surgeries. My
primary generalized needs include driving and shopping. My primary
occupational use is at a computer, with a large monitor about 30" from
my eyes. I also play the piano, with the music stand and keyboard
each about 20" from my eyes. I would add that the frames I'm
considering (Silhouette 7481) offer generous areas above and below the
pupils (Eye=47, Bridge=20, Vert=35). My current prescription is (Eye,
Sph, Cyl, Axis, Add):
OD -3.75 +2.75 x175 +2.00
OS -4.00 +1.50 x155 +2.00
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.
Quote
I used Varilux Comfort lenses 3-5 years ago, with a similar distance
prescription but a reading correction of only +1.00; I found the
peripheral image blur fairly annoying. Lately I've been using single-
vision lenses, sliding the frames down my nose for monitor viewing and
looking over them for reading. I can see very well in these ways, but
I've grown weary of the antics!
It's time to specialize. (It's a different kind of antics.)
Quote
Some specific issues that concern me:
1. Would I benefit substantially from the newer, individually designed
progressive lenses that use free-form technology?
In general, and to varying degrees, yes. They won't feel like SV lenses though,
and most folks don't experience a "considerable" improvement in acuity, FOV,
and/or sense of refinement.
That said, the difference will probably be much smaller than the difference
between an accurately positioned lens and one that's poorly positioned. In other
words, better quality lenses do not make up for bad opticianry.
Quote
On what basis might
I choose between, say, the Hoya iD, Shamir Autograph, Zeiss
Individual, or other models?
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.
Quote
Are there desirable alternatives at
lower technology levels and prices?
Any premium (multi-design, fully aspheric, numerous base curves, good binocular
vision, etc.) PAL that has a generous distance zone would be ok. I probably
wouldn't use a short corridor design for your situation, especially if you get
multiple pairs.
Quote
2. Would I fare better in occupational use with an "office" type lens
or with a regular progressive lens suitably adjusted (e.g., by moving
some of the "Add" power into the "Distance" prescription)?
IMO the latter.
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 sheet 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.
Quote
Many thanks for your time and effort in reading this.
David
Hope this helps,
Robert Martellaro
~~~~~~~~~~~~~~~~~~
Optician/Owner
Roberts Optical
Wauwatosa Wi.
~~~~~~~~~~~~~~~~~~
"Science is a way of trying not to fool yourself."
- Richard Feynman
-
