A re-appraisal of screening for colour vision impairments.

Screening for colour vision impairments (CVI) has been carried out in schools in the UK since 1934, but little is known about its yield or value. A survey was conducted among Sheffield schoolboys, school nurses and optometrists to determine the benefits of CVI screening. The results indicated that between 4.2 and 5.2% of boys had been identified as having a CVI, compared with the expected prevalence of 8%. Boys were ill-informed about the significance of CVI for careers planning but recognized the potential importance of having this information before making decisions about choice of subjects and examinations. Possible reasons for the low yield of screening are reviewed and alternative strategies are discussed.