A year ago I went to an optometrist and got a prescription that looks like this:
Spherical Cylinder Axis Add H. Prism V. Prism
R +1.00 -1.25 093 -- -- --
L +1.00 -1.50 070 -- -- --
I used this prescription to order glasses from Zenni and got great results.
Today I saw an ophthalmologist for a medical issue and she also evaluated my eyes for an updated prescription. She said that it had only changed a very tiny bit from my previous prescription and I might not need to get new glasses. She wrote this:
Spherical Cylinder Axis Add Prism
OD -0.50 +1.50 5 2.50 <blank>
OS -0.75 +1.75 155 2.50 <blank>
She did mention that the way that ophthalmologists write prescriptions is different than how optometrists do it, because they are interested in different things. But she didn’t explain the math.
However, I do not know how to submit the second prescription and get the right results. Does the second prescription have values that somehow offset one another once you put it all together, or is it a completely different notation? Will Zenni interpret this as simply a different way to write a prescription and get it right, or am I going to end up with glasses that look like the bottoms of Coke bottles?