OPTICAL AND RETINAL LIMITS TO VISUAL PERFORMANCE

描述（来自摘要）：本研究的长期目标是 确定光学和视网膜因素如何影响视力。具体目标 在下一个项目期间，可分为两大类：视网膜 建筑学和视觉光学。视网膜的结构决定了 限制健康个体的空间视觉质量。先前 实验表明，视觉分辨率，最重要的 在临床实践中使用的视觉功能测量是有限的 最终由视网膜马赛克中视觉神经元的间距决定。在 为了利用这一事实，开发有用的新诊断工具， 为了探究视网膜疾病，首席研究员建议 表征整个视野的分辨率地形 正常的眼睛。有了这个规范标准，两个临床 将对人群（青光眼和弱视患者）进行检查， 异常稀疏采样镶嵌的证据。另外的实验 被提出来测量视网膜对运动知觉的限制 在整个视野中，将这些结果与 分辨率，并将两张地图与已知的视觉地形进行比较， 神经元在人类视网膜作为抽样模型的测试。一个主要 对视觉分辨率的采样理论的挑战是要解释 采样镶嵌图中不规则性对视觉表现的影响。 为了解决这个问题，我们提出了一个系统的调查效果 分辨率和运动感知的不规则性 由实验者采样（谁控制的程度， 不规则性），而不是由视觉系统。另一个挑战是 将广泛接受的平行途径模型纳入 理论根据这种视网膜结构模型，视网膜是 不是一个单一的马赛克，而是一组独立的马赛克， 同时对视网膜图像进行采样， 通过视神经纤维的子集来控制大脑的视觉区域。为了 为了阐明该模型对空间分辨率的影响， 首席研究员建议调查是否更高的中心 的视觉系统重组独立的神经图像进行 平行通道，从而增加有效采样密度， 相应提高分辨率。视觉光学防止 眼睛在中央视觉中获得采样限制性能， 而不是周边视觉，只要视网膜图像聚焦良好。 为了确定在外围可以容忍多少光学散焦， 在决议开始受到影响之前，首席研究员建议， 屈光不正对分辨率影响的系统研究 极限为了充分说明这些光学效应对视觉的影响， 对光学质量的准确描述是很重要的 的视网膜图像。为此，首席研究员 提出开发一种新的技术，用于测量光传输 客观上，眼睛的功能。

DESCRIPTION (from abstract): The long term goal of this research is to determine how optical and retinal factors affect vision. Specific aims for the next project period fall in two broad categories: retinal architecture and visual optics. Retinal architecture imposes fundamental limits on the quality of spatial vision in healthy individuals. Previous experiments indicate that visual resolution, the single most important measure of visual function used in clinical practice, is limited ultimately by the spacing of visual neurons in the retinal mosaic. In order to exploit this fact to develop useful new diagnostic tools for probing retinal disease, the principal investigator proposes to characterize the topography of resolution throughout the visual field of normal eyes. Armed with this normative standard, two clinical populations (glaucoma and amblyopia patients) will be examined for evidence of abnormally sparse sampling mosaics. Additional experiments are proposed to measure the retinal limitations to motion perception across the visual field, to compare these results to a normative map of resolution, and to compare both maps with the known topography of visual neurons in the human retina as a test of the sampling model. One major challenge to a sampling theory of visual resolution is to account for the effect on visual performance of irregularity in the sampling mosaic. To address this issue we propose a systematic investigation of the effect of irregularity on resolution and motion perception using visual targets sampled by the experimenter (who has control over the degree of irregularity) rather than by the visual system. Another challenge is to incorporate the widely accepted model of parallel pathways into the theory. According to this model of retinal architecture, the retina is not a single mosaic but a set of independent mosaics, each of which samples the retinal image concurrently for transmission to specific visual areas of the brain via sub-sets of optic nerve fibers. In order to clarify the implications of this model for spatial resolution, the principal investigator proposes to investigate whether higher centers of the visual system recombine the independent neural images carried by parallel channels, thereby increasing the effective sampling density to achieve a corresponding increase in resolution. Visual optics prevent the eye from attaining sampling-limited performance in central vision but not for peripheral vision, provided the retinal image is well focused. To determine how much optical defocus can be tolerated in the periphery before resolution begins to suffer, the principal investigator proposes a systematic study of the effect of refractive error on the resolution limit. In order to fully account for these optical effects on vision, it is important to have an accurate description of the optical quality of the retinal image. For this purpose, the principal investigator proposes to develop a novel technique for measuring the optical transfer function of the eye objectively.