Multifocal electroretinography assessment of retinal responses to myopic defocus lenses.

Aim: To evaluate the short-term retinal electrical responses elicited by defocus segment lenses in emmetropic eyes using multifocal electroretinography (mfERG). Materials & Methods: A prospective cross-sectional study enrolled 14 young, healthy emmetropic participants aged 18 to 22 years with no ocular or systemic diseases. Comprehensive eye examinations were conducted, and mfERG recordings were obtained using six different condition scenarios. Retinal responses were analyzed across hexagon ring groupings defined by angular extent (Ring 1: 2.5°, Ring 2: 7.5°, Ring 3: 14°, Ring 4: 22°, Ring 5: 30°). Statistical analysis was performed to compare retinal responses across different lens types and retinal regions. Results: No significant differences in retinal electrical responses were detected across the six lens conditions for negative (N1) latency (ms), positive (P1) latency (ms), or P1 amplitude (nV/deg Conclusion: The tested defocus segment lens designs did not produce statistically detectable alterations in first order mfERG parameters in structurally intact emmetropic eyes under brief exposure. Although the analytical framework demonstrated sufficient sensitivity to identify medium to large electrophysiological effects, the current design may lack resolution for subtle retinal adaptations. Future investigations incorporating larger cohorts, prolonged optical exposure, and nonlinear analytical techniques in ametropic populations will be necessary to determine whether clinically relevant myopia control mechanisms correspond to measurable electrophysiological modulation.