Contributed Session I: The effects of monocular and binocular retinal image minification on eyestrain.

Abstract

While corrective spectacles have been worn for centuries, relatively little is known about the physical and perceptual effects associated with their optical distortions. Retinal image minification, for example, is caused by myopic spectacle correction and may also occur in near-eye displays. Previous work suggests that different amounts of minification (or magnification) between the eyes can produce perceptual distortions and oculomotor discomfort, but the extent to which these effects are problematic is unknown. In our first study, forty observers wore minifying spectacles of 2% or 4% in both eyes (binocular), just one eye (monocular), or neither eye (control). After performing a task that incorporated reading, interacting with objects, and visual search, participants reported their symptoms. Overall, participants found monocular minification to be slightly more uncomfortable than the binocular counterpart. Monocular minification produced greater eyestrain and self-reported difficulty interacting with objects. In a second study, we investigated how these two symptoms change after one hour of adaptation to monocular 4% lenses. We found that both symptoms worsened during adaptation. Interestly, the difficulty interacting with objects declined soon after the lenses were removed, while eyestrain persisted. Taken together, these studies indicate specific types of discomfort during natural tasks that may be reduced through improving optical lens designs in the future.