UCL Institute of Ophthalmology, University College London, London, UK; Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA.
New England College of Optometry, 424 Beacon Street, Boston, MA 02115, USA.
Exp Eye Res. 2018 Jan;166:96-105. doi: 10.1016/j.exer.2017.10.004. Epub 2017 Oct 16.
The formation of focused and corresponding foveal images requires a close synergy between the accommodation and vergence systems. This linkage is usually decoupled in virtual reality systems and may be dysfunctional in people who are at risk of developing myopia. We study how refractive error affects vergence-accommodation interactions in stereoscopic displays. Vergence and accommodative responses were measured in 21 young healthy adults (n=9 myopes, 22-31 years) while subjects viewed naturalistic stimuli on a 3D display. In Step 1, vergence was driven behind the monitor using a blurred, non-accommodative, uncrossed disparity target. In Step 2, vergence and accommodation were driven back to the monitor plane using naturalistic images that contained structured depth and focus information from size, blur and/or disparity. In Step 1, both refractive groups converged towards the stereoscopic target depth plane, but the vergence-driven accommodative change was smaller in emmetropes than in myopes (F=5.13, p=0.036). In Step 2, there was little effect of peripheral depth cues on accommodation or vergence in either refractive group. However, vergence responses were significantly slower (F=4.55, p=0.046) and accommodation variability was higher (F=12.9, p=0.0019) in myopes. Vergence and accommodation responses are disrupted in virtual reality displays in both refractive groups. Accommodation responses are less stable in myopes, perhaps due to a lower sensitivity to dioptric blur. Such inaccuracies of accommodation may cause long-term blur on the retina, which has been associated with a failure of emmetropization.
焦点和相应的中央凹图像的形成需要调节和聚散系统的密切协同作用。这种联系在虚拟现实系统中通常是分离的，对于有近视风险的人来说可能是功能失调的。我们研究了屈光不正如何影响立体显示器中的聚散-调节相互作用。在 3D 显示器上观看自然刺激时，测量了 21 名年轻健康成年人（n=9 名近视者，22-31 岁）的聚散和调节反应。在步骤 1 中，使用模糊的、不调节的、无交叉视差的目标使聚散在显示器后面驱动。在步骤 2 中，使用包含大小、模糊和/或视差的结构深度和焦点信息的自然图像，将聚散和调节驱动回显示器平面。在步骤 1 中，两个屈光组都向立体目标深度平面会聚，但正视者的聚散驱动调节变化小于近视者（F=5.13，p=0.036）。在步骤 2 中，在两个屈光组中，周边深度线索对调节或聚散的影响都很小。然而，近视者的聚散反应明显较慢（F=4.55，p=0.046），调节变异性更高（F=12.9，p=0.0019）。在虚拟现实显示器中，两个屈光组的聚散和调节反应都受到干扰。近视者的调节反应更不稳定，可能是由于对屈光度模糊的敏感性降低。这种调节不准确可能会导致视网膜长期模糊，这与正视化失败有关。
