Pattern-induced visual discomfort and its cumulative effects revealed by pupillary measures

Area of Science:

• Visual neuroscience
• Ophthalmology
• Human factors

Background:

• Repetitive striped patterns can cause visual discomfort (VD).
• Previous research often studied pupillary responses or VD in isolation.
• The relationship between pupillary dynamics and VD with repeated exposure needs further investigation.

Purpose of the Study:

• To investigate the covariation and evolution of pupillary responses and VD with repeated exposure to striped patterns.
• To determine if pupillary dynamics can serve as a physiological indicator of individual visual sensitivity.

Main Methods:

• Four experiments manipulated spatial frequency, central field size, and surround field size of square-wave gratings.
• Measurements included subjective discomfort ratings and pupil size.
• Individual differences in pupillary responses were analyzed in relation to reported discomfort.

Main Results:

• Higher spatial frequencies and larger pattern areas increased both pupillary constriction and discomfort.
• Repeated exposures led to cumulative discomfort and decreased baseline pupil size, indicating visual strain.
• Individuals reporting higher discomfort showed weaker pupillary constriction and stronger late redilation, a paradoxical dissociation.

Conclusions:

• Pattern-induced discomfort evolves over time and varies among individuals.
• Pupillometry shows potential as a sensitive physiological tool for assessing visual sensitivity and discomfort.
• The findings clarify the relationship between visual stimuli, discomfort, and pupillary responses.