Subjective quasi-vector-based refraction with a conventional phoropter.

Abstract

To introduce a novel methodology for subjective refraction based on power vectors with a conventional phoropter. A conventional phoropter was used to measure power vector components of refraction (M, J0 and J45) directly by using the sphere power (for M measurement) and the cylinder power combined with the Jackson cross-cylinders (for J0 and J45 measurements). Conventional subjective refraction was also performed, and this result was mathematically transformed into power vector notation for comparison purposes. Visual acuities with the conventional prescription and the quasi-vector-based prescription were compared. Refractive error from 40 healthy participants was measured by conventional and quasi-vector-based subjective refraction. No differences were found between methods for any of the power vector components of refraction (p > 0.21 in all cases). The visual acuity achieved with the prescriptions yielded similar values (p = 0.85). Subjective refraction can be measured directly in power vector notation using a conventional phoropter without any additional adaptation and computation.