VISUAL-VESTIBULAR INTERACTION WITH LOW-VISION AIDS

意义重大。许多低视力患者中枢视力受损，但 不能成功地使用望远镜，尽管理论上 从放大中获益。这可能是因为视力康复 带望远镜的眼镜受限于放大后的不稳定性 在非自主头部运动和协调运动期间的视网膜成像 视觉搜索所必需的眼球头部运动。视网膜图像 稳定性通常由视觉-前庭-眼睛反射提供。 (VVOR)，由前庭-眼睛反射与 视觉和预测机制(视觉-前庭相互作用，VVI)。 可伸缩眼镜的VVOR性能必须定量 适当放大，避免动力的大幅减损 头部运动时的视觉敏锐度。尽管这很重要，但知识 缺乏关于衰老和病理因素对人类的影响 垂直VVI。 目的和方法。总体目标是定量评估 VVI在垂直平面上的机制，作为有用视力的决定因素 在生理性的头部运动中戴着可伸缩的眼镜。眼睛和 磁头移动将使用磁搜索线圈进行测量。其效果 垂直VVOR上的可伸缩眼镜将被定量 以主动和被动头部的生理范围为特征的 正常视力和低视力成人的速度和频率。 这些发现将与视觉引导的单独测量相关联 追踪。对VVI和不可预测运动的跟踪的影响， 亮度和对比度降低、衰老、病理性眼球震颤和视觉 将对场缺陷进行研究。瞬时值之间的关系 垂直视网膜图像滑动速度和动态视力将 研究了与望远镜使用的观看策略有关的内容 眼镜。通过研究眼睛和头部的水平和垂直运动 在不受限制的视觉搜索中，实验将识别 望远镜最优视觉搜索策略的特点 眼镜。改进搜索策略以最小化视网膜图像 还将评估不稳定性和搜索时间。此数据将 加强对人类垂直眼球运动的基本了解，并提供 临床洞察临床低视力中的一个重要问题。

Significance. Many low vision patients have impaired central acuity but cannot successfully use telescopic spectacles despite the theoretical benefit from magnification. this may be because visual rehabilitation with telescopic spectacles is limited by instability of the magnified retinal image during involuntary head movements, and during coordinated eye-head movements necessitated by visual search. Retinal image stability is ordinarily provided by the visual-vestibulo-ocular reflex (VVOR), produced by interaction of the vestibulo-ocular reflex with visual and predictive mechanisms (visual-vestibular interaction, VVI). VVOR performance with telescopic spectacles must be quantitatively appropriate to magnification to avoid substantial impairment of dynamic visual acuity during head movements. Despite this importance, knowledge is lacking regarding the effects of aging and pathologic factors on human vertical VVI. Aims and Methods. The overall aim is to quantitatively evaluate mechanisms of VVI in the vertical plane, as determinants of useful vision with telescopic spectacles during physiologic head movements. Eye and head movements will be measured using magnetic search coils. The effect of telescopic spectacles on vertical VVOR will be quantitatively characterized in the physiologic range of active and passive head velocities and frequencies, in normally sighted and low vision adults. Findings will be correlated with separate measurements of visually guided tracking. The effects on VVI and tracking of unpredictable motion, reduced luminance and contrast, aging, pathologic nystagmus, and visual field defects will be studied. The relationship between instantaneous vertical retinal image slip velocity, and dynamic visual acuity, will be studied in relation to viewing strategies employed with telescopic spectacles. By studying horizontal and vertical eye and head movements during unrestrained visual search, experiments will identify characteristics of optimal visual search strategies with telescopic spectacles. Modification of search strategy to minimize retinal image instability and search time will also be evaluated. This data will enhance basic understanding of human vertical eye movements, and provide clinical insight into an important problem in clinical low vision.