I have astigmatism. It’s -0.5 at 80° in my right eye, -1.0 at 100° in my left eye. Meaning it’s 10 degrees off the vertical axis, different in each eye, symmetric to the face.
My “eye doctor” – my opthalmologist? — is a good doctor. Well educated, does a good job as a doctor. He gave me a straight -0.5 / -1.0 myopia prescription after measuring “some astigmatism”, said “this is fine”.
Then I went to a not-a-doctor guy. A licensed optician? Optometrist? Skilled and well-educated. He took the time to measure the precise degree of astigmatism and was careful to prescribe a close and practical match to the measured astigmatism. I had no idea he would do that, and no expectations of any difference whatsoever. And: Those glasses are MUCH better. I see better, see clearer, can work forever, don’t get tired in the eyes or head. Feel sharper.
I’m kind of reluctant to add this last part as it probably seems implausible, but my experience with this more detailed prescription for astigmatism is that it has allowed my depth perception to improve. Slowly. I thought I was imagining it, but it does make sense according to the optometrist and scientific papers. Basically if you get a better signal to the brain, you get better processing, better learning, better adaptation. And less tired.