Or, if the astigmatism is mild enough, they won’t even correct for it in contacts, but they will in glasses, since there’s no penalty for putting the full correction in the glasses.
For example, my contacts are a standard -2 diopter in both eyes, but my eyes are more like a -1.75 and a -2 with very slight astigmatism.
My glasses (worn on Saturday mornings primarily) are fully corrected in each eye, because it’s just a matter of pushing the right buttons on the lens grinding machine to get the correct diopter and astigmatism corrections for each lens, but my contacts are standard -2.00 early presbyopia contacts (I am 42, after all), because my optometrist and I agreed that going to the trouble of having different contacts for each eye for a 0.25 difference in diopter and the extra cost of getting toric lenses for what amounts to extremely mild astigmatism just wasn’t worth the trouble. Basically what eastcheap is saying for the contacts.
Very interesting. I wear “monovision” contacts (right eye prescribed for distance, left eye for reading). Both had astigmatism correction. But when my presbyopia got a bit more severe, I had trouble getting enough depth of field (is that the right term?) in my reading lens: I could wear a lens that would focus on my smart phone, or a different lens that would focus on my computer screen, but not one lens for both. (the other eye was busy with distance, so it wasn’t available) The optometrist’s solution was to drop the astigmatism correction in the reading contact. Now I can focus on the smart phone *and *on the computer screen with the same prescription.
Interestingly, the only thing I ever got from astigmatism correction was eyestrain while reading. Now I insist that the doctor just leave it alone. I don’t think they like it much, but it always seems to work out better that way. It also makes going back-and-forth with my OTS contacts a lot less unpleasant.
In fact, my experience with heroic correction efforts in general has been that what works great in the refractor usually doesn’t work worth a darn in a random pair of frames.