My doctor fitted me with contacts that have no astigmatism correction in them. I’m not wearing the contacts on the weekend, or the bookends of the weekday, so I’d like to make things as easy as possible on my visual cortex by having 0 cylinder spherical normalized glasses instead of my ~1D cylinder aspherical grind glasses that give me a lot of vertigo. (In high school they told me my inner ear was defective. Oddly my inner ear works better when I have contacts on my eyes. Switching back and forth though causes more issues than wearing the glasses constantly.)
I have a test lens kit, but when I get into the range of that astigmatism adding more power doesn’t help my acuity enough to notice. I could use a Stenopeaic slit to find the ends of the volume of confusion and go for spherical equivalent in the middle, but wouldn’t that cause part of the image to be in hyperopic defocus? Is that going to slow my recovery down? Or does is it a neutral stimulus because there is hyperopic and myopic defocus at the same time?
I know tackling cylinder first is unusual, as is large drops in cylinder at once, but cylinder in contacts over -10D is hard to get. The doc is already unhappy with the lack of choices he has available with just spherical correction.