The effect of lens-induced anisometropia on sterolocalization

Abstract

Little research has been done to study the effect of anisometropia on the ability of subjects to localize an object in space using binocular depth cues. Rendering a patient artificially anisometropic is similar to prescribing an unbalanced refraction or inducing anisometropia in a monovision contact lens fit. We investigated the effect of induced anisometropia on stereolocalization. Spectacle lenses were used to create the anisometropic conditions and all subjects were pretested for isometropia while wearing their best distance refractive corrections. Thirty-eight subjects judged the distance of a floating vectographic Quoit\u27s Ring target under varying amounts of anisometropia in a featureless field. The amounts of anisometropia induced ranged between 0.50 D and 1.75 D. The results indicate that there is no statistically significant difference in the ability to stereolocalize with up to 1.00 D of anisometropia, however, beyond this limit a statistically significant decrease in performance clearly exists