Occupational Psychophysics to Establish Vision Requirements

Purpose. To develop and implement a comprehensive procedure for determining vision requirements for different vocational and occupational tasks. Methods. Evaluations performed for more than 10 state agencies and businesses were conducted over a period of approximately 9 years. The procedure included a literature review, an assessment of potential visual functions to address, a formal job analysis, interviews with incumbent workers, obtaining advice and recommendations from subject matter experts (experienced incumbents and administrators), development of job-related simulation studies, linkage of simulation results to the job analysis, a review of appeals and critical incidents, a thorough assessment of work environments and conditions, and final recommendations. Results. Examples of occupational simulations for quantitative job-related task performance for best-corrected visual acuity, uncorrected visual acuity, color vision, peripheral vision, the use of one vs. two eyes, naïve vs. experienced incumbents, and impoverished visual conditions are presented. Changes in task performance and confidence ratings were obtained for various levels of degraded vision. Discussion. This procedure, referred to as “occupational psychophysics,” provides a quantitative systematic method of defining the vision requirements for various essential job functions. In conjunction with the frequency of performance, requirements at entry to the job, safety, reasonable accommodation, alteration of the work environment, and administrative issues, this approach provides a quantitative, rational basis for establishing job-related vision requirements.