Key Takeaways

• Research presented at the 44th Congress of the ESCRS found that a simple preoperative test using a phoropter could accurately predict the success of laser blended vision surgery
• This form of LASIK for the treatment of presbyopia corrects one eye for distance and the other for near
• Using the test before laser surgery had a high predictive value for the patient's postoperative tolerance of blended vision

A standardized preoperative phoropter-based binocular tolerance test accurately predicted whether laser blended vision surgery would benefit a patient undergoing LASIK, according to research presented at the 44th Congress of the ESCRS.¹ The retrospective analysis was presented by Brendan Cummings, MB ChB, BAO, MRCSI(OPHTH), a consultant ophthalmologist at the Wellington Eye Clinic in Dublin.

A phoropter was used to identify the correct lenses to maximize each patient's distance vision. Then, the patient was asked to mentally benchmark this as 100%. Next, one of the patient's eyes was defocused by making it myopic, and they were asked how this compared. The whole process was repeated but with the other eye defocused. If patients said their vision was at least 80% as good with one eye defocused, this suggested they would be able to blend the vision from their eyes successfully and they were suitable candidates for laser surgery. The test can also identify which of a patient's eyes is dominant so that it may be treated for distance vision, with the nondominant eye treated for near vision.

The study included 1,341 patients with various refractive statuses (myopia, hyperopia, or emmetropia). Using the test before laser surgery identified a small number of patients who were not suitable candidates for the treatment (30 people or 1.66%). There was also a very high rate of success following the test and laser surgery, with 96.9% of patients successfully adapting to their laser blended vision.

Dr. Cummings said, "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. This is true for all patients regardless of their prescription prior to surgery."

1. Cummings B, Buscombe C, Cummings AB. A preoperative phoropter binocular tolerance test predicts 96.9% success in laser blended vision. Paper presented at: 44th Congress of the ESCRS; September 13, 2026; London, United Kingdom. Accessed September 14, 2026. https://pagv3.virtual-meeting.org/escrs/escrs2026/en-GB/pag/session/98120