To compare binocular visual function of pseudophakic patients having modified monovision (0.75 diopter [D] anisometropia) with that of patients having conventional monovision (1.75 D anisometropia).

Prospective observational study.

Eighty-two patients that underwent bilateral implantation of a monofocal intraocular lens were recruited at 3 months postoperatively. Modified monovision was simulated by adding a +0.75 D spherical lens to the nondominant eye, while conventional monovision was simulated by adding a +1.75 D spherical lens. Binocular corrected visual acuity (VA) at various distances, binocular contrast VA (contrast VA) and that with glare (glare VA), and stereoacuity were evaluated.

With modified monovision, mean binocular corrected intermediate VA at 1.0 m was 20/19 and near VA at 0.3 m was 20/51, and stereoacuity was 125 ± 100 seconds of arc. Mean binocular intermediate VA at 1.0 m was significantly better with modified monovision than with conventional monovision (P = .0001), while near VA and intermediate VA at 0.5 m were significantly worse (P < .0001). Mean binocular photopic and mesopic contrast VA and glare VA tended to be better with modified monovision than with conventional monovision, but the difference was not significant. Mean stereoacuity was significantly better with modified monovision than with conventional monovision (P = .0020).

Modified pseudophakic monovision provided excellent binocular VA from far to intermediate distances, although near VA was worse than that with conventional monovision. Contrast VA with and without glare tended to be better and stereoacuity was significantly better with modified monovision, suggesting that this method is useful for correcting presbyopia without marked impairment of binocular function.