Ida Caroline Mann was educated at Wycombe House School in London, and after passing the Civil Service Girl Clerk's examination, got a job at the Post Office Savings Bank. She wanted to be a physician, and despite family opposition, enrolled at the London School of Medicine for Women. She graduated in 1914 and was qualified in both medicine and surgery in 1920. She had not yet chosen a specialty, so applied for all junior positions available. She was appointed as the Ophthalmic House Surgeon at St. Mary's Hospital, London, beginning a lifelong dedication to eye research and treatment. During her medical studies she had developed an interest in embryology, and now wrote a doctoral thesis on the embryology of the human eye, earning a D.Sc. in 1924. She became a Fellow of the Royal College of Surgeons in 1924, one of only six women at the time. By 1927, she had risen considerably in her profession by establishing a private practice on Harley Street, London, and securing an honorary staff post at Moorfields Eye Hospital. In 1944, she married Bill Gye, Director of the Imperial Cancer Research Fund. After World War II, they moved to Perth, Western Australia, where Dr. Mann identified an epidemic of trachoma, a serious eye disease that can cause blindness, in the native people in the Kimberleys. She traveled extensively in Western Australia in order to examine and treat patients there. She advocated better housing and sanitation to improve their overall health as well as the trachoma crisis. Dr. Mann published many articles and several books on eye anatomy and eye disease. She also wrote about her travels and findings under her married name Ida Gye or a pseudonym, Caroline Gye; these were China 13 and The Cockney and the Crocodile. She was appointed a Dame Commander of the Order of the British Empire in 1980.