IERI. Losses in Nighttime Visibility Caused by Transient Adaptation

This is the authors' abstract. We don't add key points for this paper.

Research on transient visual adaptation is concerned with the quick changes in sensitivity which the eye makes as it adjusts to variations in luminance levels. Investigations reported here provide a description of transient adaptation effects at luminance levels comparable to those found in nighttime highway lighting conditions. Findings indicate that for downward changes from a low luminance to an even lower one, smaller losses were observed than those found at higher luminance levels. Visibility loss breaks down at the lower limit of 0.002 to 0.02 fL (0.0069 to 0.069 cd/sq m). Individual differences in the amount of visibility loss for a given luminance change, whether upwards or downwards, were found to be large. Within the limits examined, the size of the target has no effect on the degree of visibility loss as measured by the interval between the beginning of the transition from one background to another and the onset of the test-letter presentation.