Everyone has certain theoretical vision correction ( Rx) based on the shape
of the eye, but younger people can make their eyes adapt by physically
changing the shape of the eye. When you get older, you are not able to do
that as easily, so the desired Rx is closer to the theoretical Rx. It is
usually best to not over prescribe if your eyes can adapt to a "better than
theoretical" Rx.

But bottom line is that in any profession, some are better than others, and
some are incompetent. BTW, never go to an ophthalmologist to get an eye exam
(unless you have a eye disease or some other serious eye condition). Go to
an OD (optometrist) whenever possible for your exam.

First off, you won't change the physical shape of your eye by wearing, or
not wearing, or wearing the "wrong" glasses. Only the crystalline lens
changes shape. It has a "posture" that plays tricks sometimes, but adult
eyes don't change their basic shape because you're looking through a piece
of plastic.

Second, you usually get better answers if you post more specifically. We
don't know if you're talking about a prescription for nearsightedness,
astigmatism or bifocals. We presume you weren't dilated beforehand, and that
your prescription wasn't determined by a machine.

In refraction (the one-or-two procedure) the test conditions can influence
the outcome. The refractionist's instructions can also. I bet it's
significant that your second prescription from Dr. N was much the same as
the first.

There are some legitimate reasons why it might happen. At age 39, making
your distance vision better often means making your near vision worse. Your
focusing ability (accommodation) is partly a matter of posture and habit,
and losing the ability between 35 and 50 causes gradual changes in posture.
New glasses cause _sudden_ changes in posture (accommodation/convergence),
which might not be well tolerated.

There are plenty of hyperopes who couldn't "accept" full correction for
newly-emerged hyperopia, and myopes who didn't like newer, lesser
prescriptions. Possibly you're one of them. If we knew your age and your
prescription, we might have suggestions about what to expect next.

At the end of refraction, ask to compare the eye chart through your old
glasses with the new prescription in the phoropter (one-or-two thingy). If
you don't see as well with the new prescription, he'll usually run through
it again, more carefully. If it's still not as good as your glasses, and
he's smart, he'll change your prescription very little.

-MT, OD