Abstract
Purpose: :
Illinois lifeguards do not have a required minimal visual acuity for certification. Various agencies have attempted to define the visual acuity requirements needed for effective lifeguarding; some have advocated a 20/30 threshold similar to police, fire, and other rescue professions, while others have advocated a 20/20 threshold. Prior to setting a lifeguard certification visual acuity threshold in Illinois, it is desirable to predict the impact of implementing a new visual acuity exclusionary criterion. To our knowledge, no epidemiological studies have been published to describe the distribution of visual acuity in lifeguards. The purpose of this pilot observational study was to determine the prevalence of usual-corrected distance binocular visual acuity among Illinois lifeguards.
Methods: :
The GuardVision Vision Test was administered to 4,509 Illinois lifeguards (ages 15-22 years). This LogMAR-based distance visual acuity test assesses the lifeguard’s usual-corrected binocular visual acuity at ten-feet. Subjects received credit for the last full acuity line they read correctly. The number of subjects passing the screening with visual acuity thresholds of 20/30 and 20/20 was analyzed.
Results: :
At a 20/30 visual acuity threshold, 4,368 lifeguards passed the vision screening while 141 (3.1%) would have been restricted from duty. At a 20/20 visual acuity threshold, 1,786 lifeguards passed the vision screening while 2,723 (60.4%) would have been restricted from duty. In this cohort, a 20/20 visual acuity threshold would restrict more than 18 times the number of lifeguards from duty than a 20/30 visual acuity threshold.
Conclusions: :
A usual-corrected binocular distance visual acuity threshold of 20/20 would restrict a larger number of Illinois lifeguards from duty than a visual acuity threshold of 20/30. The closest published cohort comparison shows that 4.1% of adults in the United States have usual-corrected binocular distance visual acuities of 20/50 or worse. The 3.1% of lifeguards in Illinois with usual-corrected binocular distance visual acuities of 20/30 or worse in this study indicates that Illinois lifeguards tend to have better usual-corrected binocular distance visual acuities than the average adult. This study does not address the impact of VA on lifeguard performance.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment