Henry Lindo Ferguson, known as Lindo, was born in Clerkenwell, London, England, on 7 April 1858, the son of Louisa Ann Du Bois and her husband, William Ferguson, an analytical chemist who became a brewer and founder fellow of the Chemical Society. The family moved to Burton on Trent in 1861 and to Dublin, Ireland, in 1866. Lindo Ferguson entered the Royal College of Science for Ireland in 1873. After a year he gained one of two royal scholarships in industrial chemistry, but he decided instead to study medicine and entered Trinity College, Dublin, where he won a gold medal for his preliminary studies in arts.
Ferguson qualified in medicine in 1880 and then decided to train in ophthalmology, becoming FRCSI in 1883. That year he emigrated to New Zealand with his mother and elder brother, William, having been advised to seek a better climate for his health. He chose to settle in Dunedin because it had a medical school. He was reputed to be the first trained eye specialist in Australasia, and on account of this and his personable demeanour developed an extensive private practice, also carrying out ear, nose and throat surgery. Ferguson took up the position of ophthalmologist to Dunedin Hospital on 1 January 1884. On 19 November at St Paul's Church, Dunedin, he married Mary Emmeline Butterworth.
In 1886 Ferguson was appointed lecturer in diseases of the eye in the University of Otago; he was made professor of ophthalmology in 1909. Because of his association with both the medical school and the hospital he fully appreciated their inter-relationship. His awareness of the needs and problems of the two institutions was heightened by his friendship with Dr F. C. Batchelor, an outspoken medical educationalist and hospital reformer and a colleague at the medical school. After a commission of inquiry into conditions at Dunedin Hospital in 1890 – prompted by Batchelor, Ferguson assisted in the design of a new hospital building, the Campbell Pavilion.
Ferguson was appointed dean of the Faculty of Medicine (in effect dean of the medical school) in 1914, following the death of the previous incumbent, Professor J. H. Scott. It was widely considered that the medical curriculum was in need of revision and that relations between the Faculty of Medicine, the university council and the hospital board required clarification. The process of reform was hampered but not halted by the outbreak of the First World War, and new buildings for the pathology and bacteriology departments were in use by 1917. After the war Ferguson succeeded in extending the medical course from five to six years in line with Australian practice; it was a very unpopular move and was carried by the Senate of the University of New Zealand in spite of considerable criticism from those who preferred practical over theoretical training. Another reform which was difficult to achieve because of senate opposition was the removal of the anatomy and physiology departments from the main university and their establishment in new buildings at the medical school in 1927.
In the course of his work as dean, Ferguson encountered lack of understanding, jealousy and at times bitter hostility. He was able to overcome such obstacles by his kindly, dignified manner, quiet persistence and social ease. He and his wife were renowned for their hospitality. His dealings with politicians were amiable and one of his chief goals was to educate and befriend successive ministers. These personal qualities probably assisted him to increase the medical school's endowments to over £110,000. He himself made a large donation which formed the basis of a scholarship eventually known as the Ferguson Fund.
Ferguson was several times president of the Dunedin Club and a noted patron of the arts. He built up a valuable collection of paintings which eventually passed to the Dunedin Public Art Gallery. His wider interests enabled him to take a very broad view of medicine and medical training.
Ferguson belonged to various medical associations and was the recipient of honorary degrees and fellowships from American, Australian and British institutions. As a leader of the profession in New Zealand, he was president of the New Zealand Medical Association in 1896 and of the New Zealand Branch of the British Medical Association in 1920. In 1918 he was appointed a CMG; he was knighted in 1924 and was made a commander of the Order of St John in 1937.
Ferguson retired from the staff of Dunedin Hospital at the beginning of 1935 after more than 50 years' service, but continued as dean of the medical school until the end of 1936. Although he was well regarded as New Zealand's pioneering ophthalmologist, it is for the latter post that he is best remembered. Mary Ferguson predeceased her husband in 1944; a son survived him. Henry Lindo Ferguson died in Dunedin on 22 January 1948.