George G. Eyre was educated at the Diocesan College, Cape Town, matriculated in 1877, and was awarded the Bachelor of Arts (BA) degree by the University of the Cape of Good Hope in 1879. Proceeding to the University of Edinburgh he qualified as Bachelor of Medicine (MB) and Master of Surgery (CM) in 1885. Returning to the Cape he was licensed to practice on 26 May 1887 and for some time acted as locum tenens for Dr Charles J. Egan* in King William's Town. Back in Cape Town he became house surgeon at the New Somerset Hospital in 1888, from where he published a contribution in the South African Medical Journal (first series) in October that year. Thereafter he was appointed as additional medical officer of Robben Island and surgeon-superintendent of the Old Somerset Hospital. In 1890 he was diagnosed with possible pulmonary tuberculosis and moved to Bloemfontein. He was licensed to practice in the Orange Free State in October 1891 and practiced there to the end of 1893. In that year he contributed another article to the newly founded (second) South African Medical Journal.
Leaving Bloemfontein he settled at Claremont, Cape Town, for the rest of his life, becoming medical officer of health for Claremont, and honorary medical officer of the Wynberg Cottage Hospital. At the Second South African Medical congress, which opened in Cape Town on 27 December 1893, he read a paper on "The treatment of phthisis in the Orange Free State and the Karoo".
At the beginning of 1894 Eyre took over as editor of the South African Medical Journal, succeeding Dr Alexander Edington*, and edited it until it ceased publication at the outbreak of the Anglo-Boer War in October 1899. At the Third South African Medical Congress held in Natal in 1895 he read a paper on "Medical journalism in South Africa; being a report on the work and principles of the South African Medical Journal during the years 1894 and 1895". He found the work very demanding and to prevent his resignation he was made editor-in-chief and the following sub-editors appointed early in 1896 to lighten the load: E.B. Fuller* of Cape Town (Public Health), C.C. Elliot of Cape Town (Hospital Notes), E.C. Long* of Maseru (Notes), and W.T. Harris of Port Elizabeth (Nursing).
In 1897 Eyre contributed an article on "The Orange Free State" to a book by W.C. Scholtz*, The South African climate; including climatology and balneology and discussing the advantages, peculiarities and capabilities of the country as a health resort - more particularly with reference to affections of the chest (pp. 143-154). He was one of the first practitioners in and around Cape Town to specialize in anaesthetics (the first was Dr George W.B. Daniell*). He was a member of the Cape of Good Hope (Western Province) Branch of the British Medical Association by 1895 and in later years served as its secretary, and in 1908 as vice-president. He supported the formation of the South African Medical Association in January 1897 and soon became a member. A kind, gentle and painstaking man, he was a devout Anglican and for many years a churchwarden of St Saviour's Church in Claremont. He died of renal disease.