According to research presented at the 44th Congress of the European Society of Cataract and Refractive Surgeons (ESCRS), a simple preoperative vision test may help identify which patients with presbyopia are most likely to adapt successfully to laser blended vision. 

Laser blended vision corrects one eye primarily for distance vision and the other for near vision, relying on the brain’s ability to combine the two images. Although the approach can reduce dependence on glasses, not every patient can tolerate the resulting difference between the eyes.

Brendan Cummings, consultant ophthalmologist at the Wellington Eye Clinic in Dublin, Ireland, and colleagues evaluated whether a standard phoropter-based assessment could predict tolerance before surgery.

During the test, clinicians first used the phoropter to maximize binocular distance vision, which patients were asked to consider as 100%. One eye was then deliberately defocused to simulate short-sightedness, and patients rated the resulting quality of vision. The process was repeated with the opposite eye. Patients who judged their vision to remain at least 80%as good with one eye defocused were considered likely to tolerate blended vision. The assessment also helped determine ocular dominance, informing which eye should be targeted for distance and which for near vision.

The study included 1,341 patients with a range of baseline refractive errors. Preoperative testing identified 30 patients, or 1.66%, as unsuitable for treatment. Among those proceeding to surgery, 96.9%successfully adapted to laser blended vision.

“We found that a simple, low-tech assessment of perceived distance vision and eye dominance has a very high predictive value for a patient’s tolerance of blended vision,” said Cummings, adding that the approach could allow clinicians to screen out unsuitable candidates before treatment.

Commenting on the findings, ESCRS Secretary Joaquín Fernández, who was not involved in the research, said reliable criteria for patient selection remain important as the number of surgical options for presbyopia expands. While newer technologies for assessing sensory dominance are beginning to emerge, these tools are not yet widely accessible and so it is still worth clinicians considering simple, more clinically accessible tests.  

“Therefore, studies such as the present one are of considerable practical value,” said Fernández, “as they provide clinically applicable information for patient selection, treatment planning and the future assessment of new technologies from a cost-effectiveness perspective.”

The study was presented at ESCRS 2026 and received no external funding.

Source: ESCRS Congress.