Also, opthos don't profit from giving prescription glasses to patients. They profit through surgery and lasik.
The two communities are apart as groups do things in higher frequencies.
Same with psychology and psychiatry to a large extent. Ones psychotherapy. Another is psychopharmacology based.
Similar thing with my field in another ten years. Therapy takes a long time. EMGs, nerve conduction, and tPA injections need groups doing their own things. So physiatry and neurology do that at high frequency. The rehab will be all therapists