I recently had two eye exams done at two different facilities (one ophthalmologist and one optometrist). I received a prescription from each, and I'm curious if they agree with each other.
One prescription says (for each eye):
-4.00 : +0.75 x 180°
and the other prescription says (for each eye):
-3.25 : -0.75 x 90°
I know enough about the numbers to know that the first number is my main vision correction (for nearsightedness) and the second set of numbers is for an astigmatism, but are these two prescriptions equivalent? If they are equivalent, is one form "preferred" over the other by eyeglass labs?