Eye test predicts who is a match for presbyopia LASIK

Clinical takeaway: A brief perception check on standard exam equipment can tell presbyopic patients considering blended-vision LASIK whether their brains will cooperate in advance of an operation. 

By the time presbyopia makes reading glasses unavoidable, many patients start asking about a surgical way out. Blended-vision LASIK is among the more appealing answers, promising clear vision at every distance with no glasses at all. The approach delivers for most patients who choose it. But it fails for a minority, with the failure surfacing only after the operation. 

Blended vision refines monovision, the older approach of correcting one eye for distance and one for near, which unscreened has historically succeeded in less than three-quarters of patients, per the published literature. Tolerance for the deliberate mismatch between the eyes varies from patient to patient, and surgical planning has typically worked around that variation with fixed monovision targets rather than anything tailored to the individual.

What has been missing is a quick, in-office way to establish before the procedure whether a given patient will adapt and how large an offset to program. The current screen, a contact lens trial, takes days of lens wear.  

The test simulates blended vision in the phoropter before any surgery. With both eyes fully corrected for distance as the benchmark, one eye is then blurred toward near focus and the patient rates how the combined view compares. Patients who rated that simulated view at least 80% as good as their full correction kept their blended vision 96.9% of the time. Failure, defined as a second procedure converting the near eye back to distance, occurred in 3.1% of the 1,341 consecutive patients who cleared that threshold and went on to surgery, most often within the first year. A bigger difference between the eyes did not raise the risk: failures were no more common in patients given larger offsets.

Failure rates were similar regardless of a patient's starting prescription, at 3.45% in myopic patients and 3.00% in hyperopic patients, with none among the small group who began with neither. The offset clustered between 1.50 and 1.75 diopters in 62.5% of treatments, a band the investigators read as the working range for blended vision.

The Dublin-based investigators retrospectively reviewed consecutive patients undergoing LASIK with blended-vision targeting. The near eye was set to the largest blur each patient tolerated while still rating the simulated view at 80% or better. Before surgery, 51.8% of patients were myopic, 44.7% hyperopic, and 3.4% emmetropic.

The test requires no equipment beyond the phoropter already standing in every ophthalmologist's office, so adoption faces no purchasing or training bottleneck. The finding awaits peer-reviewed publication. 

"Both patients and specialists need reliable criteria to determine whether an intervention is appropriate and to predict which patients are most likely to benefit," said Joaquín Fernández, MD, PhD, ESCRS secretary and medical director of the Andalusian Ophthalmology Institute at Vithas Hospitals in Almería, Spain, who was not involved in the research. 

"Although new technologies are currently being developed to assess sensory dominance in a more innovative way, these tools are not yet available to all professionals," he concluded. "Therefore, studies such as the present one are of considerable practical value, as they provide clinically applicable information for patient selection, treatment planning and the future assessment of new technologies from a cost-effectiveness perspective." 

Source: Cummings B, et al. (2026 Sep 13) 44th Congress of the European Society of Cataract and Refractive Surgeons. A preoperative phoropter binocular tolerance test predicts 96.9% success in laser blended vision