Abstract
Laser eye protection is used to prevent eye injuries in laboratory and military settings. Protecting against lasers requires filtering of light at the wavelengths where these systems operate. If that filtering includes wavelengths in the visible range, significant changes in color detection and perception may occur. The purpose of this study was to determine the effects on color vision of filtering at different locations in the visible band and how well those effects were predicted by a model based on color processing in CIE color space. Ten filters were tested and these varied in the width of the filtered wavelength band, but were similar in depth (optical density). The filters were designed to protect against lasers operating in different regions of the visible spectrum. Color vision was assessed with the Farnsworth-Munsell 100 Hue Test (FM100) and a color naming test that had subjects identify the hue of colored symbols presented on a dark background. Twelve observers with normal vision participated. The baseline error scores (ES) on the FM100 ranged from 0 to 32. ES changes with filters ranged from 4 to 112 points. Color naming errors, like the ES, varied depending on the filter bandwidth. Color naming performance for many hues declined to nearly 100 percent mis-identifications and this was well predicted by the model. There was also evidence that blocking light in some spectral regions had a greater effect on color discrimination than blocking it in others.