excessive minification?

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

kite@execpc.com - 28 Jan 2006 05:46 GMT

I just got a new pair of glasses; same material as my old ones (Hoya
1.70 index), nearly same prescription (Old prescription: OD -8.50,
-1.50 axis 059; OS -8.00, -1.25, axis 108. New prescription: OD -8.25,
-1.75, axis 065; OS -8.00 -1.25, axis 110). The frames are similar in
width but slightly narrower top-to-bottom. Until now, I've used the
same frames over and over for three years (and three new sets of
lenses).

Why on earth would things look significantly smaller through my new
glasses? The left eye prescription is no different at all except for
two degrees on the axis, and the right just took a quarter diopter off
the sphere and added it to cylinder, which I understand is more or less
a wash. Narrower frames don't cause changes in the amount of lens
distortion, do they? I'm very sensitive to slight changes, so I'm not
surprised that it's taking me some time to get used to the new
prescription, but things just seem *smaller* with the new lenses, as
though the sphere power had been cranked up beyond what I really need.
But it hasn't been! Is there any explanation I'm missing here? My
eyes really feel strained (though I suppose I will get used to the
glasses more over a few days' time). It's really tempting to just put
the old ones back on since there's no real difference in prescription
and they just feel more comfortable. I could have them checked to be
sure the lenses were made properly, but I'd be quite surprised if they
weren't (one lens was already re-made because it arrived scratched).

Reply to this Message

acemanvx@yahoo.com - 28 Jan 2006 07:31 GMT

by any chance do they sit further from your face? Vertex distance is
the best explanation. Maybe the different materials make a small
difference but then it doesnt explain why contacts dont minify at all.
Try reading some small letters as far away as you can with your old
glasses and with your new glasses. If there really is more
minification, you will have to move closer with the new glasses.

Reply to this Message

Dom - 28 Jan 2006 10:32 GMT

> by any chance do they sit further from your face? Vertex distance is
> the best explanation. Maybe the different materials make a small
> difference but then it doesnt explain why contacts dont minify at all.
> Try reading some small letters as far away as you can with your old
> glasses and with your new glasses. If there really is more
> minification, you will have to move closer with the new glasses.

I would like to congratulate Aceman on at last contributing a useful and
accurate answer to this newsgroup! Without mentioning a plus lens or a
bifocal, uncorrected acuities, cylinders, etc. The new frame sitting
further from the face is exactly what I had thought of too. But rather
than moving closer to the object of regard, I would suggest having the
frame adjusted on the face to sit closer to the eyes.

Dom

Reply to this Message

Dan Abel - 28 Jan 2006 23:17 GMT

> > by any chance do they sit further from your face? Vertex distance is
> > the best explanation.

> I would like to congratulate Aceman on at last contributing a useful and
> accurate answer to this newsgroup! Without mentioning a plus lens or a
> bifocal, uncorrected acuities, cylinders, etc. The new frame sitting
> further from the face is exactly what I had thought of too. But rather
> than moving closer to the object of regard, I would suggest having the
> frame adjusted on the face to sit closer to the eyes.

My thoughts also.

Signature

Dan Abel
dabel@sonic.net
Petaluma, California, USA

Reply to this Message

kite@execpc.com - 29 Jan 2006 04:03 GMT

Thanks for the suggestion. Both frames sit very close to my eyes,
though; I don't think the new ones could get closer. I'm still getting
a lot of eyestrain with the new pair. The only other thing I noticed
is that the new frames have a rather more strongly curved profile than
the old ones, which were quite flat. I'm beginning to think I should've
just stuck with the frames that I'd been happy with for years! For
some reason my lenses even look thicker in this frame, though I don't
believe it's any wider. (There are numbers on the frame -- 50, a
little square, then 18. I think that corresponds to size? My old
frame says 51, square, 19; presumably it was slightly larger.)

I'm 32 and don't need any bifocals or have anything else unusual going
on; my prescription has been pretty stable for a while. My right eye
is difficult to correct because I have some scarring from corneal
dystrophy (lots of corneal erosions six or seven years back). However,
I was quite happy with my last prescription, which is why I wanted to
stick with this optical office. I was very reluctant to agree to any
change at all, but figured the -.25 off the sphere and onto the
cylinder probably didn't matter. Heck, the only reason I was getting
new glasses at all was because I put a lovely scratch right through the
middle of one of my lenses. They talked me into this new frames,
saying they couldn't order me another pair of the ones I already had
because Brooks Brothers was a skeezy off-brand.

I will give them more time, though; I'm a fussy myope, but I don't want
to be totally obnoxious.

Reply to this Message

Dick Adams - 29 Jan 2006 05:25 GMT

> Both frames sit very close to my eyes, though; I don't think the new
> ones could get closer. I'm still getting a lot of eyestrain with the new
> pair. The only other thing I noticed is that the new frames have a
> rather more strongly curved profile than the old ones, which were
> quite flat.

Lenses should be flat to the eyes. Wraparound makes no sense.
Not all eyeglass makers and fitters seem to know that. I had to plead
to get my frames flattened on some occasions, and have had to do it myself on
others. There is a best distance for any given lens design, but it is relatively
unimportant compared to the other thing.

--
Dicky

Reply to this Message

Rate this thread: