Why use ViSS?

ViSS is an entirely objective test that is swift and easy to administer. By comparing the child's response to visually stressful and visually unstressful stimuli, the program calculates whether visual stress has significantly detrimental effects on the child's performance. Alternative methods of identifying visual stress are more subjective and can be unreliable. The main methods are to ask children questions about whether they experience symptoms of visual stress (to which their answers can be misleading or inconsistent) or to carry out an overlay screening test. Unfortunately, in an overlay screening test almost all children will select a coloured overlay although only about 20% of the children continue to use it voluntarily. In other words, four out of every five unselected children screened for coloured overlays don't really need them, and if overlays are provided for these children they will soon stop using them. Clearly, this is a huge waste of staff time and resources. ViSS provides a swift, cost-effective solution to this dilemma, and facilitates rapid provision of appropriate treatment to those that really need it, without wasting effort in unnecessary screening and provision.