Effects of Target Clarity on Monocular Blur Suppression: A Video Simulation of Simultaneous Vision Multifocal Lens Correction.

OBJECTIVES

To examine the effects of target clarity on monocular blur suppression while using simultaneous vision multifocal lenses through video simulation.

METHODS

Twenty healthy adults (mean age 20.8±6.1 years) were presented with circular targets at three spatial frequencies (3, 6, and 18 cpd). Gaussian blur filter simulated full refractive correction (0 pixels of blur) and two levels of residual refractive error correction (10 pixels and 20 pixels, respectively). For each target condition, a 50% transparent image with the same spatial frequency was superimposed, with its blur gradually increasing by 0.1 pixels every 0.2 s. The time until participants detected additional blur compared to the initial state was measured and analyzed.

RESULTS

Participants perceived blur significantly earlier in the two levels of residual refractive error models (10 and 20 pixels of initial blur) compared to the full refractive correction model across all spatial frequencies (p < 0.017). Spatial frequency also influenced blur perception, with detection occurring significantly earlier at higher cpd values across initial blur conditions.

CONCLUSIONS

Residual refractive error appears to impair the function of monocular blur suppression, aggravating the perception of ghost images. Full refractive correction is therefore essential for effectively suppressing these unwanted visual artifacts.