I just started wearing contact lenses a few weeks ago, and was given
Biomedics 55 Toric lenses (for my left eye). It's all nice and good -
it feels comfortable and I don't even feel it most of the time
(although it takes me longer to put on this lens than the Biomedics 38
I was given for my right eye) - if not for the little problem with
astigmatism.

The crux of the problem is that my left eye has astigmatism (cyl?) of
-3.00, and Biomedics apparently only makes toric lenses up to -2.25.
(However, apparently Softlens 66 has up to -2.75.)

The first lens I got gave me such blurred vision that after 5 days of
wearing it, I couldn't take it any longer and went back to the
optometrist, who ordered another lens with an increase in the
compensation for myopia (overcorrection?) to compensate for the
undercorrection for my astigmatism. This new lens, while much better,
doesn't give me as acute a vision as I would like. She told me that if
this lens wouldn't give acute enough vision, the Bausch and Lomb
Softlens 66 would be another possible lens to try since they
manufacture lenses that compensate for a higher amount of astigmatism.

So, after a week or so of wearing the new lens, I went back to the shop
and was seen by another optometrist, who told me that the Biomedics
toric was the only toric lens that'd fit my eye (at my first fitting I
think they actually tried the Softlens 66 but said the Biomedics
rotated less), and if I wanted any improvement it could only be on the
right lens (and not the left), unless I went for permanent lenses (an
idea that I'm not too keen on).

So what I'm wondering is whether I could actually try the Softlens 66
even though it supposedly fits less well than the Biomedics Toric, and
whether it is true that the Softlens 66 wouldn't fit my eye (is it
because of a difference in base curves?), and also whether the
difference between -2.25 and -2.75 for astigmatism would be enough to
justify more rotation in the lens. I'm also not sure if it's possible
to just go back to the shop and ask if I can just try the Softlens 66
(even worse because I keep asking for a change in the prescription for
sharper vision and hence keep getting new trial lenses - I have 2.5
pairs currently).

I'm not sure what my prescription is, but this is what's written on the
blister pack of the last trial lens I got (for my left eye):
SPH -5.00  CYL -2.25  AX 170  BC 8.70  DIA 14.50

Also, is it a good fit if later on in the day, the toric lens
(Biomedics) tends to rotate and stay rotated such that my vision from
my left eye becomes very unclear and no amount of blinking can make it
clear again (unless I really really blink a lot)?

Lastly (slightly unrelated), is there a problem with the fit if, when I
put the lenses into my eye, I have to move it around a bit and get some
air trapped under the lens to pop up before the lens will stay in
place?

Thanks (and sorry for all the questions and the trouble)!