Peter graduated with Honours from NSW University in 1990 and worked as an Emergency Medicine Doctor at Royal North Shore Hospital. He was awarded  the Australian Gold Medal in the Emergency Medicine Primary Exam.

After 4 years of Emergency Medicine he transferred to eye surgery and later graduated from Sydney Eye Hospital. He was appointed as the Professorial Senior Registrar in his final year at Sydney Eye Hospital and worked with the Sydney University Department of Ophthalmology which deals with complex eye disease.

He was awarded the Sir Norman Rose travelling scholarship and furthered his surgical experience by living in England where he underwent a Corneal and Cataract Surgery Fellowship at the renowned Bristol Eye Hospital. In recognition of his high level of training to an international standard, the Royal British College of Ophthalmology granted him dual registration as a specialist eye surgeon in both Britain and Australia.

Dr Sumich is an Associate Eye Surgeon at Sydney Eye Hospital and is a Consultant Eye Surgeon at Westmead Hospital where he instructs in cataract surgery. He is a member of The Australian and also the American Society of Cataract and Refractive Surgeons. Dr Sumich serves on the New South Wales Ophthalmic Services Advisory Committee and is a 15 year member of the Australian Medical Association. He is a Clinical Lecturer with the Sydney University Department of Ophthalmology at the Save Sight Institute.

Dr Sumich has published many scientific papers and is an article reviewer for The British Journal of Ophthalmology Online.