I have astigmatism and short-sightedness. In your prescription they put several numbers to define how the lenses for your glasses should be built.
Your prescription can change over time, but I have always had astigmatism, that hasn't changed.
However, something has always confused me, some eye-doctors seem to prescribe me glasses with indications for astigmatism and less adjustment for nearsigthness, while others just give me more adjustment for nearsightness without astigmatism adjustment.
From the article above, it seems you have to have 3 numbers in your prescription, however I don't remember ever seen a third number in mine. It might be something to do with difference in standards in different countries.
I have had prescriptions like:
- -1.25: this number is the adjustment for my short-sightedness, we call it "increment" in my country, although it may seem counter-intuitive. But the proper name is diopter.
- -0.75 +0.8: As I said, it seems I may be missing one number, but it is clear a 0.75 diopter for my short-sightedness and +0.8 diopter for the astigmatism.
As personal experience, I think that when they prescribe me glasses with both elements I feel better. However I would like to understand if there is a practical difference.
Is it the same to have a prescription with a higher diopter for short-sightedness, basically a more powerful lense, than a prescription with less short-sightedness adjusment and a separate adjusment for the astigmatism?
What is the practical difference? Because in the end I manage to see, I just think I "feel" better with the glasses that have both adjustments.