Notes:

Assuming that we will be able to overcome the practical difficulties associated with implementing the liquid crystal lens, thereby achieving perfect retinal images, what will be the benefit?

The answer is that there are two broad categories of ways in which improved image quality can yield practical benefits. One is to improve the vision of the person wearing the corrective lenses, and the other is to improve the vision of the optometrist or ophthalmologist who is looking into a patient's eye for diagnostic purposes. The difference in these two categories is the direction of light propagation - into the eye, or reflected out of the eye. In both cases the benefit is an improvement of image contrast.