A comparative field survey of the effects of two alternative lighting systems, a parabolic downlighting system and a ceiling suspended, lensed- indirect lighting system, on computer workers in a virtually windowless office was conducted. A questionnaire, collecting data on work content, perception of ambient environmental conditions including office lighting, work-related health symptoms, job stress and job satisfaction, and self-reported productivity was completed by 96 workers. Results show that the lensed-indirect lighting system was rated significantly more favorably on several subjective lighting quality scales, and significantly more appropriate for computer based work. Workers reported less problems with glare on their computer screen and with work being hindered, fewer eye problems (tired eyes, trouble focusing eyes), better productivity, and significantly higher satisfaction for the lensed-indirect system compared with parabolic lighting.