Analysis of Variables Measured in the Visual Screening of University of Birmingham Freshmen and a Critical Review of Visual Screening Methods and Approach

Abstract

This investigation analysed the variation of the visual functions measured by the University of Birmingham visual screening technique, for the years 1958 to 1967. A review of the history and development of screening techniques and survey of relevant literature was carried out. The efficiency and repeatability of the University screening method was determined, firstly by questionnaire and re-screening follow-up methods, and secondly by a more controlled, experimental procedure. Comparison was made between this screening method and commercially available screeners. In addition an evaluation of the sub-tests was made in respect of their accuracy, repeatability, sensitivity and specificity. Conclusions were reached as to which subtests should be included in the screening batteries, and which should be omitted because their contribution to the overall efficiency of the screeners was very limited. A preliminary investigation was made into the effects on efficiency of changing the referral standards. The criteria for accepting any specific level of efficiency were discussed.