Table of Dk values for Silicon Hydrogels

Recently, in another thread, I asked about such a table.

I just found one, so I'll post the link here, in case anyone else is looking
for such a table:

http://www.siliconehydrogels.com/images/editorial/BRIAN_TIGHE/table1_L.jpg


If the figures on the chart are correct, I find one thing I find a little
surprising:

The chart shows both Acuvue Oasys and O2 Optix as having higher Dk values
than Purevision. Yet neither are approved for 30 days wear, as is
Purevision.

Biofinity has the second highest dK, second only to Night&Day. Yet they are
currently approved in the US only for daily wear. (I believe they have been
approved for 30 days wear in other countries, however, and will probably
eventually have that approval in the US.) (Why does such approval always
take longer in the US?)

I wonder though, why Oasys and O2 were not submitted for 30 day approval?
(Or, if they were submitted, why not approved?)

According to the chart, Advance only has a dK of 60, much lower than the
others. I'm surprised that a si-hy lens would have such a low dK. (And
surprised that my eye doc would tell me (see thread about toric si-hys) that
the Advance has a higher dK than Purevision, and is approved for 30 day
wear!)

 

There's more to extended wear than oxygen permeability. The Acuvue
lenses both tend to collect deposits more than the PureVision and N&D
lenses.

Your OD's confusion about Acuvue Advance is just an excellent example
of why you shouldn't assume a professional knows everything about his
or her profession. Informing yourself is always a good idea.