COLOR photography of the human and animal fundus is no new achievement. It was used by Wesley, Morax, and Reyburn in the 1930's2 and has been used by many other workers since, both experimentally and clinically. But owing to the intensity of illumination required and the fact that the illumination must be concentrated to little more than a point, a carbon-arc source has been the illuminant usually chosen. This has always been notoriously unreliable for serial work, however.
For many years there have been feelings of concern among some ophthalmologists that harmful effects to the patient's eyes could result from the use of carbon-arc lamps, and, although this possibility has been strongly disputed by others, a constant search for an alternative light source has been conducted. None of those used, however, has provided every advantage sought for such an exacting piece of equipment.
Then the British Thompson Houston Company,
PRINCE JH, COWAN JD, SMITH NA. FURTHER DEVELOPMENT IN RETINAL PHOTOGRAPHY. AMA Arch Ophthalmol. 1955;53(2):267-270. doi:10.1001/archopht.1955.00930010269016