I requested five letters of recommendation, picked three for my CAS (ophtho, medicine, neurology), and then four for my ERAS (medicine, neurology, pediatrics, family medicine).
I applied to many programs, a couple here, and a couple in each city that I applied to an ophthalmology residency if that was a city I'd rather live in than here. I hope I can coordinate interviews for with the program directors for the TY and prelim programs I applied to with my interview days for ophtho. The most desireable TY and prelim programs are very competitive, from what I hear.