Lets look at the clinical example first.
One of the main jobs of an optometrist is to look into the patient's eye with specialized clinical instruments. For example, a fundus camera is a compound optical system which uses the eye's optical system as the objective lens for taking pictures of the retina, blood vessels, optic nerve head, and other anatomical structures at the back of the eye, to document the state of health of a patient's eyes. Thus the quality of fundus photographs, and ophthmic imaging in general, is limited by any optical imperfections of the patient's eye. Therefore, anything we can do to improve the patient's optical system, the more the doctor is going to benefit by improved diagnostic imaging, which translates to improved patient care for the public.