Since vision happens mostly in the brain, simply selecting a lens which focusing light at a certain point in your eye is not the only thing to optimize for. You also have to optimize for the processor behind the sensor which, at least until more advanced vision models are made, is going to be purely subjective.
Is it possible for the lens to focus light perfectly, and the brain to process that as blurrier than if the light were focused imperfectly?
I would imagine that, no matter how the brain were processing the image, the image being focused exactly on the retina is an objective truth, and that an exactly-focused image must be clearer to the brain than a blurry image.
That is true for the spherical part of the lens. When you start to look into the correction of astigmatism (done by the cylindrical component of the lens) it become a whole lot more complicated.
