Color Vision Screener Test

The use of colour in transport and other visually-demanding, working environments has increased significantly in recent years. This is largely due to rapid advances in colour display technologies and lighting systems. It has become more important to be able to screen efficiently for colour deficiency and to quantify accurately the severity of colour vision loss.

Approximately 8% of males and 0.5% of females have some form of congenital colour vision deficiency. The absence of the abnormal functioning of red/green (RG) and /or yellow/blue (YB) chromatic mechanisms leads to reduced chromatic sensitivity as well as changes in the perceived colour of objects.

The most common colour screening protocols in occupational health and primary healthcare are based on the use of Ishihara test plates. These protocols vary greatly and often fail normal trichromats or pass subjects with congenital colour deficiency, depending on the number of errors accepted as pass. There is also great variability of outcome the applicants failing some testes and passing others. Manu of the applicants that fail current protocols have adequate residual colour sensitivity whilst others that pass, often exhibit severe deficiency.

The Colour Assessment and Diagnosis (CAD) test detects and classifies both congenital and acquired colour deficiencies. The CAD test also quantifies the severity of both Red/Green (RG) and Yellow/ Blue (YB) loss of colour vision.