Visual Performance as a Function of Clear Central Aperture Diameter with a Defocused Myopic Periphery

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Peripheral myopic defocus is a key factor in myopia progression.
• Understanding its impact on visual performance is essential for myopia control strategies.

Purpose of the Study:

• To evaluate how different clear central aperture sizes, combined with peripheral myopic defocus, affect various visual performance tasks.
• To determine the optimal aperture size for minimizing visual performance disruption.

Main Methods:

• Thirty visually normal subjects were tested with five spectacle conditions: three single-vision lenses with 10°, 12.5°, and 15° clear apertures and peripheral defocus (+3.5 D), progressive addition lenses (PALs) with +3.5 D addition, and single-vision lenses (SVLs) without defocus.
• Visual performance was assessed using static and kinetic visual field sensitivity, reading rate and comprehension, head movements, and saccadic eye movements.

Main Results:

• Reading rate and comprehension remained consistent across all conditions.
• Static visual field sensitivity decreased in eccentric regions for all tested apertures compared to SVL and PAL conditions.
• The 15° aperture demonstrated superior performance, showing minimal differences in head movement and saccadic tracking compared to SVL and PAL conditions.

Conclusions:

• A 15° radial aperture with peripheral myopic defocus offers the least adverse effect on visual performance.
• These findings support the use of specific aperture designs in spectacles and contact lenses for effective myopia management with minimal visual compromise.