The City University Colour Vision Test

Historical Significance: This book test for abnormal colour vision is derived from the Farnsworth D15 test and designed to be equivalent to it. The first page is for demonstration followed by 10 test plates. Each of the 10 test pages has a central reference colour and four surrounding test colours. The patient's task is to identify which of four test circles is most similar in colour to the reference. Three of the test colours have been selected so that they are approximately isochromatic with the reference for the protanope, deuteranope, or tritanope. The fourth colour was selected to be just noticeably different from the reference for a color-normal. The inventor was Professor Robert Fletcher (b1925) MSc (Tech), FSMC (Hons), FBOA (Higher Diploma), D.Orth, DCLP, FCOptom, FAAO. Professor Fletcher taught in the Department of Optometry & Visual Science at the City University and its predecessor, the Northampton Institute of Technology from 1950 until his retirement, leading it from 1966 to 1980. He was appointed the first Professor of Optometry outside the USA and trained over 10,000 students. During his career he formed close links with the optical industry and professional associations and has made a major contribution to optometry in the UK and the development of optometry in other countries. His special expertises were orthopics, contact lenses and colour vision deficiencies.