O.D. sph -0.75 cyl -0.50 axis 170. Here we are talking about your right eye, it comes from the latin Oculus dexter (eye on the right).
sph=sphere, here is where it says whether they are prescribing for short or longsightedness. in your case it's for far sight
cyl=cylinder is where they measure for astigmatism (this causes blurred vision)
axis is a measurement for the cylidrical lens of the glasses you are being prescribed.
O.S. is where they have looked at your left eye (oculus sinister in latin) all the words mean the same thing, obviously.
I'm pretty sure that your eyes aren't too bad -0.75 ist to high a value.
Hope this helps.