Re: PureVision Toric lenses

In article <8zgMg.630$jF.392@xxxxxxxxxxxx>, "DK" <none@xxxxxxxxxx>
wrote:

My Rx is in the -7 range, with astigmatism in the -1 range. My previous
toric contacts over the past couple years were Frequency 55 (for one eye)
and Soflens 66 (for the other), but both lenses rotated out of place
frequently and I wasn't real pleased with them.

The Purevision Toric is the same design as the SL66 toric and most of
time perform the same.

My new optometrist just tried a couple different Biomedic toric lenses on
me, but those seem to rotate a lot too.

Now he's ordered me PureVision Toric lenses to try, which he says are
stiffer and hopefully less likely to rotate out of place. I haven't gotten
them yet, but was wondering what opinions you eye docs have of these lenses,
since they are pretty new. Are they less likely to rotate than Biomedics and
similar lenses and do they tend to work well for hard-to-fit patients?

As I wrote above, but, as your doctor said, the different modulus of the
material *may* help keep it more stable. If your cyl is -1, you should
be using the -.75 lens, not the 1.25.

Also, how does a lens' water content affect tear levels in theeye? Do the
ones with higher water content tend to absorb the tears more like a sponge,
and make the eye feel dryer? Or does it work the opposite, where all the
water in the lens keeps the eye moist?

The dehydration effect has to do with both the water content of the lens
AND the plastic's ability to hold the water in the lens matrix. There
are 55% water lenses that dry up like an old sponge and others that stay
reasonably and efectively pliant and moist with moderately dry eyes and
low humidity.

It looks like PureVision lenses have less water content than the previous
ones, but from what I understand, in silicone hydrogels, the silicone is
what transfers the oxygen rather than the water in regular hydrogels, is
that right?

Yes, and therefore the material is oxygen transmission stable, compared
to older plastics that vary depending upon hydration.


Any and all opinions on PureVision toric lenses would be appreciated!

I find it to be an excellent lens. I also use a number of others as
appropriate to achieve the best fit and vision and as is available for
that person's prescription.

Your other post/query: cleaning. Most any non-abrasive soft lens
cleaner to rub and rinse off will be great. You can also use the
so-called n0-rub multipurpose products (the ones ok for silicone lenses)
and rub that product on the lens to get pretty good cleaning action
prior to soaking for disinfection.

LB, O.D.
.

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