Whoops.  Hit send prematurely.  Let's try that again.

Your headers seem to indicate that you're posting from Australia.  At
least in the US, one would have to get a valid prescription from a
licensed medical practitioner (a medical doctor or doctor of optometry)
before getting and lenses.

I had difficulties with a certain trial lens parameter (Acuvue Advance
8.7) and got a different one from my O.D.  The 8.7 felt great in the
office and supposedly looked good when examined on my eye.  They would
feel different after a few hours, and didn't center well on my eyes.
After a trying the 8.3 for a week, my O.D. wrote a prescription
after I called in that it felt OK - no follow up visit.

I've been told that serious problems are extremely rare with daily wear
lenses as long as they're properly disinfected.  However - I hear some
people take shortcuts such as rinsing with tap water, licking lenses,
unclean hands, reusing solutions, dirty lens cases, etc.  Some even
extend the lens wearing period beyond the recommended period.

Ciba and Acuvue daily contact lenses may or not be interchangeable,
depending on the shape of your eye and other factors.

In the U.S., contact lenses are prescribed by licensed eye care
professionals.  I suggest that you contact your eye care professional
for a consultation.

DrG

these two lenses are different.  the plastics that they employ are
different and the parameters are different.

it's best to have an eyedoc get you some Focus Daily trial lenses, let
you try them out, and check with a biomicroscope (slit lamp) to be sure
they fit appropriately.

Hi Mary

I would go back to your optometrist as they are the most qualified to
judge whether you can change your prescription. I wouldn't chance it
with my eyes to try something else without knowing what problems it
would cause.

I now buy my lenses on the web. I use the 1 day acuvues and I get the
90 packs instead of the 30 packs.

Here are some sites in Oz that sell lenses:-
http://www.easycontacts.com.au
http://www.webcontacts.com.au

and if your in America
http://coastalcontacts.com

Dave