Enhanced Uncorrected Distance Visual Function Of The Near Eye In Monovision Refractive Surgery: A Large-Scale Retrospective Analysis
Published 2026 - 44th Congress of the ESCRS
Reference: FP31.09 | Type: Free paper | DOI: 10.82333/gfh3-kq15
Authors: Dr Avinoam Shye Shahar* 1 , Dr Natalie Zeghebih 2 , Dr Daniel Lemaitre 2 , Mr Tzachi Sela 3 , Mr Gur Munzer 3 , A/Prof. Eric Gabison 2 , A/Prof. Michael Mimouni 4
1Ophthalmology,Rambam Health Care Campus,Haifa,Israel, 2Rothschild Foundation Hospital, Paris Cité University,Paris,France, 3Care-Vision Laser Center,Tel Aviv,Israel, 4Ophthalmology,Rambam Health Care Campus,Haifa,Israel;Ruth and Bruce Rappaport Faculty of Medicine,Technion - Israel Institute of Technology,Haifa,Israel;Care-Vision Laser Center,Tel Aviv,Israel
Purpose
To quantify the enhanced myopia effect, where Uncorrected Distance Visual Acuity (UDVA) exceeds optical predictions for residual myopia in monovision refractive surgery. We aimed to determine if eyes treated with LASIK or PRK for myopia and aimed to mopia (the "near eye"), achieve better distance vision than naturally myopic eyes for the same magnitude of refractive error, and to isolate the optical and neural mechanisms driving this dissociation.
Setting
A large scale retrospective comparative study of patients treated at a high-volume refractive surgery clinic between 2014 and 2024.
Methods
We evaluated 43,879 eyes, categorizing them into three cohorts: PRK Monovision, LASIK Monovision (post-operative residual myopia -0.50 to -3.00 D), and a Natural Control group (virgin eyes with matched natural myopia). Originally hyperopic eyes were excluded. Defocus curves plotting UDVA against Spherical Equivalent (SEQ) were generated. "Visual Gain" (Observed UDVA minus Expected UDVA based on controls) was calculated. Subgroup analyses evaluated the impact of various parameters on visual gain.
Results
Treated eyes demonstrated significantly better UDVA than controls across the myopic range. At the critical -1.50 D monovision target, PRK eyes achieved a mean UDVA of 0.52 decimal (approx. 20/40), outperforming LASIK (0.40 decimal) and natural controls (0.24 decimal, approx. 20/80) (p<0.001). While control eyes exhibited a classic pinhole effect (smaller pupils improved vision), both PRK and LASIK eyes in the refractive sweet spot (-1.25 to -1.75 D) showed a positive correlation (PRK +0.064; LASIK +0.021 lines/mm), indicating larger pupils beneficially recruit induced peripheral aberrations. Neural adaptation contributed significantly, with visual gain peaking at 3 months post-operatively.
Conclusions
Post-refractive surgery eyes exhibit a robust enhanced myopia capability, possibly driven by an extended depth of focus from induced aberrations and neural adaptation. PRK induces a more potent effect than LASIK. Surgeons can leverage this phenomenon to safely target higher degrees of myopia (e.g., -1.50 to -1.75 D) in the near eye, maximizing reading durability without compromising binocular distance orientation. Trial lenses over virgin eyes significantly underestimate the true visual outcome of monovision.