Dynamics of the accommodative response and facility with dual-focus soft contact lenses for myopia control

Objective: To assess the impact of using dual-focus soft contact lenses for myopia control on the dynamics of the accommodative response and facility.Methods: 24 young adult myopes were fitted with dual-focus soft contact lenses for myopia control (MiSight (R)) and single-vision soft contact lenses (Proclear (R)). The WAM-5500 open-field autorefractor was used to measure the dynamics of the accommodative response (magnitude and variability) in binocular conditions, with accommodative data being gathered from the dominant eye, at three viewing distances (500 cm, 40 cm, and 20 cm) during 90 s. Also, the binocular accommodative facility was assessed with the WAM-5500 autorefractor. All participants performed the same experimental protocol with the dual-focus (MiSight) and single-vision (Proclear) soft contact lenses, with both experimental sessions being carried in two different days and following a counterbalanced order.Results: This study showed greater lags of accommodation with the MiSight than the Proclear lenses at near distances (40 cm: 1.27 +/- 0.77 vs. 0.68 +/- 0.37 D, corrected p-value = 0.002, Cohen-d = 0.90; and 20 cm: 1.47 +/- 0.84 vs. 1.01 +/- 0.52 D, corrected p-value = 0.007, Cohen-d = 0.75), whereas a higher variability of accommodation was observed with the dual-focus than the single-vision lenses at 500 cm (0.53 +/- 0.11 vs. 0.23 +/- 0.10 D), 40 cm (0.82 +/- 0.31 vs. 0.68 +/- 0.37 D), and 20 cm (1.50 +/- 0.56 vs. 1.15 +/- 0.39 D) (corrected p-value < 0.001 in all cases, and Cohen-ds = 0.67-2.33). Also, a worse quantitative (27.75 +/- 8.79 vs. 34.29 +/- 10.08 cycles per minute, p = 0.029, Cohen-d = 0.48) and qualitative (23.68 +/- 7.12 vs. 28.43 +/- 7.97 score, p = 0.039, Cohen-d = 0.45) performance was observed with the MiSight when compared to the Proclear lenses.Conclusions: The use of dual-focus soft contact lenses for myopia control alters the dynamics of accommodative response and facility in the short-term. Although this optical design has demonstrated its effectiveness for myopia control, eye care specialists should be aware of the acute effects of these lenses on accommodation performance.