City Research Online

Abstract

Functional colour vision is the result of a symphony of parallel biological processes that enable humans with normal trichromatic colour vision to make efective use of colour encoded information. The use of colour coding in transport and other visually demanding working environments has increased signifcantly in recent years and it has become more important to be able to screen efficiently for colour vision deficiency and to quantify accurately the severity of colour vision loss.

The outcome of conventional methods of colour vision assessment in current single- and multi-test protocols were investigated to determine the current state of colour vision assessment. An exploratory study evaluated the outcome of a test commonly used in these protocols; the Farnsworth D-15. The new ‘Colour Vision Screener’ (CVS) test was developed to address many of the issues present in conventional methods of colour vision assessment and a preliminary study was carried out to determine the optimal test parameters. Upon determination of the test parameters the CVS was evaluated and validated across three separate experiments to: establish the performance of the CVS in least affected individuals with congenital colour vision deficiency, determine the reliability of the CVS, and examine the validity of the CVS through an international multi-centre study.

Current single- and multi-test colour assessment protocols fail to achieve their aims and are unable to achieve high sensitivity, or reliably quantify the severity of red/green or yellow/blue loss. The CVS was found to have very high test-retest reliability, and high sensitivity and specificity. The test does not suffer from several limitations present in conventional methods of colour vision assessment and allows for the swift, accurate, and reliable detection of congenital and acquired colour vision deficiencies.

Publication Type:	Thesis (Doctoral)
Subjects:	R Medicine > RA Public aspects of medicine
Departments:	School of Health & Psychological Sciences > Optometry & Visual Sciences School of Health & Psychological Sciences > School of Health & Psychological Sciences Doctoral Theses Doctoral Theses

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