Purpose: To develop a model of the relationship between ocular disease and exposure to visible and ultraviolet-B (UVB) wavelengths. Methods: Our model for personal ocular exposure is: Qp = N Roa Qa Ft That Teye G, where N is the number of days in the period; Roa is the ocular-ambient exposure ratio (OAER); Qa is the ambient exposure on a horizontal plane; Ft is the fractional time spent out of doors; That and Teye are diminutions due to the use of hats or eyewear; and G is a geographic modifier. The OAER is defined as the quotient of the exposure to the corneal tangent plane and that on a horizontal plane. It is determined by instrumenting groups of people engaged in similar jobs. Ambient exposure, Qa, is derived from meteorological data bases. Fractional time out of doors, Ft, is determined through the use of a job history interview. Results: We have instrumented 260 individuals engaged in 9 activity categories in all four seasons. We found that OAER's are generally higher in the UVB than in the visible (17% versus 6%). There is variability by job category in the UVB (highest OAER was 25% for daycare workers; lowest OAER was 5% for construction). Hat use reduced ocular UVB exposure by 50% but had little impact on visible exposure. Conclusions: Our model provides realistic estimates of lifelong personal ocular exposures in the UVB and visible spectral regions. It embodies aspects of job function, personal behavior, and the temporal and spatial distribution of the ambient illumination.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience