Singh Neeraj K, Kollbaum Pete
School of Optometry, Indiana University, Bloomington, Indiana, USA.
Ophthalmic Physiol Opt. 2025 Sep;45(6):1456-1467. doi: 10.1111/opo.13533. Epub 2025 May 28.
Chronic hyperopic defocus from inadequate accommodation during near tasks may be associated with axial eye growth. This study examined accommodative behaviour and retinal defocus in myopic and emmetropic children after 1 h of continuous electronic device use.
Thirty-four children (17 per group, aged 7-17) participated, including myopes wearing dual-focus (DF) myopia control contact lenses (MiSight 1-day) and uncorrected emmetropes. In phase one, on-axis aberrometry data were collected at distances from 4.00 to 0.20 m, corresponding to target vergences from -0.25 to -5.00 D. In phase two, measurements were taken every 10 mins, as children watched a movie at 0.20 m for 60 min. Local refractive state measures were calculated from aberrometry measures and pooled within pupil areas corresponding to DF lens central and treatment zones. Retinal defocus was calculated by subtracting target vergence from the measured refractive state. Linear mixed-effects models analysed group, target vergence and time effects on defocus, adjusting for pupil diameter.
Myopes with DF lenses showed greater hyperopic defocus (+0.58 D, p = 0.001) than uncorrected emmetropes during on-axis viewing. Hyperopic defocus increased significantly over time in both groups with near viewing (p < 0.001). Myopic defocus induced by DF lenses was still present but decreased following 50 and 60 min of near viewing (p = 0.05 and p = 0.007, respectively).
Periods of sustained near viewing of up to 1 h increased hyperopic defocus in both groups. However, DF contact lenses still introduced myopic defocus in myopic subjects throughout this time, supporting their potential to slow axial eye growth during periods of sustained near viewing. Further work will be helpful to understand how the sustained near viewing model and associated results of the current work relate to the real-world environment, which may include potential breaks and/or longer total near viewing durations.
近距离任务时因调节不足导致的慢性远视性离焦可能与眼轴生长有关。本研究调查了近视和正视儿童连续使用电子设备1小时后的调节行为和视网膜离焦情况。
34名儿童（每组17名，年龄7 - 17岁）参与研究，包括佩戴双焦点（DF）近视控制隐形眼镜（MiSight 1天型）的近视儿童和未矫正的正视儿童。在第一阶段，在4.00至0.20米的距离收集眼轴像差测量数据，对应目标聚散度为-0.25至-5.00 D。在第二阶段，当儿童在0.20米处观看电影60分钟时，每10分钟进行一次测量。根据像差测量结果计算局部屈光状态指标，并汇总到与DF镜片中央和治疗区域相对应的瞳孔区域内。通过从测量的屈光状态中减去目标聚散度来计算视网膜离焦。采用线性混合效应模型分析组、目标聚散度和时间对离焦的影响，并对瞳孔直径进行校正。
在眼轴观察期间，佩戴DF镜片的近视儿童比未矫正的正视儿童表现出更大的远视性离焦（+0.58 D，p = 0.001）。在两组近距离观察时，远视性离焦均随时间显著增加（p < 0.001）。DF镜片引起的近视性离焦仍然存在，但在近距离观察50分钟和60分钟后有所降低（分别为p = 0.05和p = 0.007）。
长达1小时的持续近距离观察会增加两组的远视性离焦。然而，在这段时间内，DF隐形眼镜仍会在近视受试者中引入近视性离焦，这支持了它们在持续近距离观察期间减缓眼轴生长趋势的可能性。进一步的研究将有助于了解持续近距离观察模型以及当前研究的相关结果与现实环境的关系，现实环境可能包括潜在的休息时间和/或更长的总近距离观察时长。
