Monovision versus Blended Vision for Presbyopia Correction: A Prospective Observational Study

PURPOSE: To compare visual outcomes, quality of life, and patient satisfaction between monovision with bilateral monofocal intraocular lenses (IOLs) and blended vision combining a trifocal IOL in the dominant eye with a monofocal IOL in the non-dominant eye for presbyopia correction after cataract surgery. SETTING: Tertiary care Ophthalmology center in Mumbai, India. DESIGN: Prospective observational study with masked outcome assessment. METHODS: A total of 150 patients with bilateral cataracts who desired postoperative spectacle independence were counselled regarding two surgical strategies: monovision with bilateral monofocal IOLs or blended vision (trifocal IOL in the dominant eye and monofocal IOL in non-dominant eye). After detailed counselling, patients selected their preferred strategy. Outcomes were assessed at 6 months postoperatively. RESULTS: At 6 months, the blended group demonstrated a significantly lower mean area under curve compared to the monovision group (0.746 ± 0.130 vs 1.090 ± 0.295 logMAR·D, respectively, p < 0.001), indicating broader depth of focus. NEI-VFQ25 score was significantly higher in the blended vision group (89.1 ± 9.8 vs 83.6 ± 10.8; p=0.001). Blended vision achieved better spectacle independence for distance, near and intermediate tasks. Stereoacuity was significantly better preserved in blended vision. Blended vision, however, was linked to higher incidence of halos and decreased contrast sensitivity in both photopic and mesopic conditions. CONCLUSIONS: Blended vision provides superior continuous range of vision, better quality of life, enhanced spectacle independence, and preserved stereoacuity compared to monovision, though at the cost of increased dysphotopsia and reduced contrast sensitivity.