The Effect of Luminance Pattern on Nighttime Discomfort Glare Response (CRADA Final Report)

Technical Report · Tue Sep 30 00:00:00 EDT 2025

DOI:https://doi.org/10.2172/3006359· OSTI ID:3006359

Abboushi, Belal K. ^[1]; Miller, Naomi J. ^[1]; Royer, Michael P. ^[1]; Ormanova, Alfiya ^[1]; Irvin, Lia C. ^[1]; Rodriguez-Feo Bermudez, Eduardo ^[1]

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1. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

LED luminaires with apertures containing visually resolvable “bright” (i.e., high luminance) spots are commonly used to illuminate outdoor environments. However, the impact of the distance between LEDs, which determines spatial frequency at a given viewing distance, on perceived discomfort caused by these luminaires remains unclear. This study involved 29 participants who were each shown 68 stimuli varying in spatial frequency, intensity, diffusion level, and ambient lighting in a dark laboratory setting. Participants reported their experiences of discomfort from glare, ability to resolve individual LEDs, and afterimages. The findings revealed that increased spatial frequency heightened both discomfort and the likelihood of experiencing afterimages. It is hypothesized that the point spread function of the eye contributed to these effects, where sources began to be perceived as a single larger source with equal or greater intensity. These results suggest that LED luminaire designs should favor configurations with lower spatial frequencies to minimize discomfort. A simple quantity, direct illuminance at the eye, is recommended for use to predict discomfort from glare because it performed like other more complex models.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 3006359
• Report Number(s): PNNL--38552; CRADA-653
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES