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Ascorbic Acid and Healing of Corneal Ulcers

1950; BMJ; Volume: 2; Issue: 4689 Linguagem: Inglês

10.1136/bmj.2.4689.1145

0959-8138

Thomas A. Boyd, F. W. Campbell,

Corneal Surgery and Treatments

main problems in vision to-day is the question of what the rods are doing under photopic conditions. ConclusionEnough has been said to indicate that the rigid trichro- matic theory and the dogmatic assertion of the presence of three types of cone in the fovea of the normal eye are not entirely satisfactory.The study of specific retinal areas, functionally by the use of small fields, structurally by the use of reliable histological methods, and electrophysio- logically in other animals, is now the obvious method of approach.Further work on the same lines with colour- blind subjects can almost be guaranteed to yield further dividends.In particular, a more enlightened approach to the evolution of visual mechanisms may well gixe clues on the nature of the mechanism for colour-vision: thus, there are many indications that the colour-sense may have arisen when a central apparatus was evolved for comparing and evaluating the information already reaching the brain through separate channels previously developed for other purposes-for example, for night and day vision, for increased visual acuity, etc.The time has now come, there- fore, for a more biological and comparative approach to the subject.The working of the human eye cannot be treated in isolation as a purely physical or psychological problem; it must be studied in relation to the evolutionary history of vision as a whole.