Is there an unwritten rule regarding who should write the 3 letters of rec? I am planning on having 1 ophthalmology, 1 medicine, and 1 surgery letter. Is this okay? Or do program directors/admission committees generally expect at least 2 ophtho letters? I am asking because I am pretty sure the surgery and internal medicine letters are going to be strong letters because they are from attendings I worked with extensively who know me well. The ophtho letter will be from my PD which I presume will be a good letter. I can get another ophtho letter but it may not be as equivalent in strength as my med or surgery letter. So should I compromise strength of letter for subject? Anyone have any input? I've been searching the web and asking residents but there doesn't seem to be a clear answer. Would appreciate any input.