Bringing clarity to the clinical framework for photic phenomena and dysphotopsias through the evidence-based functional classification: a narrative review.

This narrative review aimed to explore the evidence on photic phenomena (PP) and positive dysphotopsia (PD) associated with simultaneous vision intraocular lenses (SVIOLs), with particular emphasis on refractive lens exchange (RLE) and the functional classification framework. A structured PubMed search identified systematic reviews and meta-analyses reporting PP/PD outcomes, and these findings were integrated with stratified analyses from the IOLEvidence database, restricted to standard, non-toric IOL studies in populations without comorbidities. Evidence syntheses consistently indicate lower rates of halos and dysphotopsia with monofocal and enhanced monofocal IOLs and higher frequencies with Full-DOFi designs, although heterogeneity and inconsistent PP/PD definitions limit pooled inferences. Category-based analyses suggest that Narrowed and Enhanced lenses show lower halo frequency than Full-DOFi lenses, while Extended designs demonstrate intermediate outcomes with substantial overlap. Within-category variability, particularly in the Extended group, indicates that optical design (refractive versus diffractive) may influence PP/PD more strongly than the achieved DOFi. Stratified analyses using IOLEvidence enable earlier, model-specific comparisons that anticipate clinically relevant differences before conventional meta-analyses detect them. In RLE, where preoperative lens clarity and patient expectations differ from cataract populations, preoperative symptom assessment and objective optical-quality metrics might be critical to manage postoperative dysphotopsia patient expectations.