A physiological basis for visual discomfort: Application in lighting design

<jats:p> Visual discomfort occurs when the statistics of the retinal image depart from those of natural scenes, particularly in respect of an excess energy at spatial frequencies close to 3 cycles/degree. Computer models suggest that uncomfortable stimuli are processed with a larger and less sparse neural response. Uncomfortable stimuli usually evoke a relatively large oxygenation of the visual cortex of the brain, consistent with inefficient neural encoding. The discomfort may be homeostatic. The neural computation that sustains sight is therefore likely to be more complex when the visual scene is spatially periodic, when the colour contrast is high or when saccadic suppression is impaired by flicker that is too rapid to be seen. </jats:p>