I'm experiencing very similar problems.

I had an old prescription which was fine, but I decided I wanted new
frames.

I got an exam, new glasses, but my left eye was not seeing things
clearly.

It was like there was a blurry spot on the glasses (not my eye) but I
could not see it on the lens even after meticulously cleaning it to a
perfectly clean state.  I kept wanting to rub my eye, even though it
made no difference.

I went back to my old glasses, but a few months later decided to try
again.

I felt rushed with the eye exam both times. When they ask to compare
two lenses in the test, I would want to blink to clear up my vision,
which made it hard to judge in a short period of time.

Sometimes it seems like the "contrast?" seems different between two
lenses while the sharpness also changes and I have a hard time deciding
which is better.

I felt really rushed even though I wanted to very carefully choose, and
I also wish I could just adjust it myself on my own time.  After I
would ask to look at the difference between two lenses for the 3rd
time, my optometrist was impatient and told me not to think about it so
much and to "go with my first instinct".

He wound up strengthening the prescription on the left lens, which
improved the blurryness problem a little, but it was still there and
really annoyed me, plus the strengthened prescription made things seem
strange and made me feel somewhat uneasy.

I tried another optometrist which was a bit more patient with me. My
new lenses came in, and my left eye was now seeing perfectly, but now
the same problem was happening to my right eye!

I tried to live with it for a few days, but it was getting annoying.
Fortunately I kept my old lenses, so I removed the right lens from my
glasses and put in the previous right lens.  This seemed to work pretty
well, but I noticed that the right lens still seemed to be a little bit
off, espeically when I was reading text for a long time (I'm a computer
programmer).

This was made worse one day when I must have inadvertently gotten
flashed with a bright light while out getting lunch, causing a
temporary blind spot in my right eye.  I don't remember the flash of
light, and it didn't affect my left eye, but I definitely noticed the
spot when I got back to work (where the environment is much darker).

The blind spot lasted for about 3 days, but even after it went away I
became much more conscious of my vision in my right eye, and now the
blurry spot is bugging me a whole lot more.

I'm nearsighted with astigmatism and 30 years old.  I wear my glasses
all the time that I am awake.  I don't have my prescription numbers
handy, but I can post them when I get home if needed.

If anyone can suggest anything, I would be very appreciative. Thanks!
=)

PS: I don't know if it's related, but some days I will watch TV for an
extended time (say, 4 hours, sitting about 12 feet away from a 42"
screen), but then I try to use my computer and all the text is *very*
hard to read--the text is still fairly sharp, but it seems to stretch
off like a double image. I usually wind up just giving up and taking a
nap, which seems to reset it.