Adaptation to monovision

Many patients who begin wearing monovision contact lenses report that it requires days or weeks for them to become adjusted to the anisometropia; however, it is not clear if there are measurable improvements in their vision during this period. We therefore studied both the objective and subjective characteristics of adaptation to monovision over a period of 8 weeks. Sixty presbyopic subjects wore high water content hydrogel lenses in the study. During the 8 weeks of monovision wear, there were no significant changes in the subjects' visual acuities (distance, intermediate, or near) in high- and low-luminance conditions, near stereopsis, or interocular blur suppression characteristics. Nevertheless, the subjects reported significant improvement in various aspects of visual performance during the same period. Forty-eight percent of the subjects reported complete tolerance to the vision with their correction within the first week of monovision wear and a total of 78% of subjects were completely satisfied with the monovision correction at the completion of 8 weeks wear. The improved tolerance to monovision may be related to changes in aspects of vision other than those measured in this study or may reflect a psychological adjustment to the anisometropia.