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

## TL;DR

This study shows that uncorrected vision flaws make it harder to ignore blurry images, emphasizing the need for full vision correction.

## Contribution

The study introduces a video simulation method to quantify monocular blur suppression under residual refractive error conditions.

## Key findings

- Participants detected blur faster with residual refractive error compared to full correction.
- Higher spatial frequencies led to quicker blur detection across all initial blur conditions.

## Abstract

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.