Easson was born in 1915 in Grangemouth and studied at Glasgow University where he qualified in 1938. After serving in the RAF Medical Service Easson joined the staff of Christie Hospital Manchester. After completing his training in radiotherapy Easson was appointed consultant in 1950. Easson gained an MD in 1958 at Glasgow with a thesis on leukaemia and later wrote a major paper on the curability of Hodgkin's Disease. In 1962 he became director of the Christie Hospital and Holt Radium Institute, a position he held until his retirement in 1979. In 1973 Easson was appointed professor in radiotherapy at the University of Manchester. He had an international reputation and was particularly involved in education about cancer and early detection. Easson was very active in the Royal College of Radiologists and was president from 1975 to 1977. Easson was awarded many honours, including an MSc at the University of Manchester in 1977, and the CBE in 1978. He died on 18 October 1983.