Eric Lewis Davis was born in Sydney, son of Cecil Davis, master butcher, and his wife Brenda. Medical cousins were Neville and Harold Davis and Maurice Joseph. Eric was educated at Sydney Grammar School where his excellence in the study of classics gave him the title Captain for 1932. The following year he entered medicine at the University of Sydney on an Exhibition.

Graduating with honours in early 1940, Eric enlisted in the Australian Army Medical Corps in November. In January 1941 he sailed to the Middle East where he served in Palestine, Egypt and Syria before returning to serve in Merauke in Dutch New Guinea which he described as a dreadful enclave. In 1943 a six month posting to the Army General Hospital at Concord enabled him to study for and obtain his MRACP. He completed his military service as a physician at Aitape, Wewak and Rabaul.

After the war, Eric was until 1950 a general practitioner in Mosman. He was appointed as a Clinical Assistant in Medicine at the Royal North Shore Hospital (RNSH) in 1949. Eric married Wanda Juanita (nee Trenn) in 1940. Their children were Peter Lewis born in 1947 and Susan Rose born in 1949. In 1951 Eric left this family at home to gain further medical and neurological training. He attained the MRCP Edin in 1953. After his return to Sydney, Eric entered private practice as a neurologist at St Leonards and was appointed an Honorary Associate Physician at RNSH. Honorary appointments were obtained at the Ryde and Manly District Hospitals.

In 1963 Eric established the Department of Electroencephalography (EEG) at RNSH with the author, Colleen Mc Cullough, as the first technician. It is thought that a character in one of her novels is based in part on Eric. He also established an EEG Department at the Ryde District Hospital and an EEG service at the Manly District Hospital. At RNSH he collaborated with John Grant, Honorary Neurosurgeon, in pioneering surgery for epilepsy. In 1971 when there was an upgrading of hospital appointments, Eric was given the title of Electroencephalographer and Neurologist at RNSH. He was a Consultant Neurologist at the Spastic Centre (1965-80) and at the North Ryde Psychiatric Centre (1965-75). He provided a voluntary service to the NSW Society for Crippled Children (1965-75). Between 1951 and 1958 and for a period from 1997, Eric acted as a consultant for Sydney Legacy.

Eric was noted for his forthright manner and always made his views known. With his dislike of fussy detail and stimulating personality he was popular with students. He enjoyed competitive golf and bridge and sailing from Middle Harbour. Retirement from the hospital system came in 1980 at the then statutory age of 65, however he continued for many years in private practice which ultimately became a consultancy in medico-legal matters.