Sight of undergraduates; loss of visual acuity.

MEASUREMENT of individual sight among students not only enables individual diagnosis and prescription, but may determine vocational fitness, or aptitude for particular tasks. First-rate sight may be necessary for the University Air Squadron, or again, colour-vision defect may handicap a chemist whose work depends on colour indicators, and it may be better to know of any defect before the final examination takes place. Measurement of sight in a large group sets a standard of normality which may serve for comparison between university students and persons in other occupations. A knowledge of the proportion and extent of errors of refraction in each group of the population allows estimates to be made of the cost of ophthalmic services. If no young adult population is known with worse eyesight than university students, it may be because too few groups have been studied. Undergraduates' sight will be shown to be substantially worse than that of the 18-year-old men examined by National Service Boards in 1939. The relative incidence ofhypermetropia and myopia (under atropine cycloplegia) is fully discussed in most standard text-books of ophthalmology. Duke-Elder (1949) for example, shows how the incidence varies with age, race, and geographic region. It is generally known, too, that although hypermetropia is commoner than myopia in most parts of the world, more young adults wear glasses for myopia because those with hypermetropia are more often able to overcome their handicap without strain. But in seeking to compare the visual acuity of various groups in the population difficulties are soon encountered. Many authorities provide scanty information or none concerning the frequency with which defective visual acuity may be expected. This is largely because the samples studied have referred to hospital patients or to other groups equally unrepresentative of the community with regard to age, sex, or occupation. If the correction of errors of refraction under the National Health Service has recently proved unexpectedly expensive it may partly be due to greater emphasis