Monovision: a review of the scientific literature.

We reviewed the scientific literature on monovision to compare the visual performance of monovision patients with that of others wearing more traditional prescriptions. We found that visual performance of monovision patients was comparable to that of control patients wearing a balanced binocular correction, provided that reading adds were not greater than about +2.5 D, that illumination was photopic, and that stimuli were presented at supra-threshold levels. Under these conditions, monovision patients were satisfied with their perceptual experience and performed within 2 to 6% of balanced binocular control patients on a range of occupational tasks. It is noteworthy that monovision patients had relatively more difficulty with acuity-based tasks than with tasks demanding good depth perception. With reading adds over +2.5 D, at low levels of illumination, or with near-threshold level stimuli, visual performance of monovision patients was reduced compared with controls. Subjectively, under low levels of illumination, monovision patients experienced problems with glare and halos around point sources of light.