LOW VISION READING AND FACE RECOGNITION

中心视野丧失的低视力受试者阅读速度要慢得多 比标准临床测量所预期的要多 视觉功能（例如视敏度和对比敏感度）。 研究计划的主要目标是确定 是什么限制了这组受试者的阅读表现， 探索图像增强的新技术，以规避 在没有中央视觉的情况下对阅读的视觉限制。 我们将研究正常青年和老年人的阅读表现 观察者和低视力受试者的中心暗点， 黄斑疾病，主要是年龄相关性黄斑病变。 以确定 正常周边视觉的阅读限制，正常 观察者将在人工暗点的存在下阅读文本 通过双浦肯野眼动仪稳定在视网膜上。 以来 不适当的眼睛运动可能严重限制周边阅读， 我们也将研究阅读的表现，通过呈现文本一 一个词在一个固定的视网膜位置的时间。 这项技术，众所周知 因为快速连续视觉呈现（RSVP）实际上消除了 扫视眼球运动的需要。 我们将确定 低视力受试者的周边视网膜表现得像 周边视网膜正常。 我们将测量空间相位或 位置灵敏度使用相位鉴别和游标任务。 将通过以下方法研究横向闭合（“拥挤”）效应： 在有或没有侧翼的情况下测量字母识别 模式和元对比掩码（向后和向前掩码 在时间域中）将用单词识别来测量 范例 空间欠采样将通过比较 光栅片的检测和定向辨别，以及 时间欠采样将通过比较CFF与两个- 脉冲鉴别 在每种情况下，我们将比较性能 中心暗点的低视力受试者与正常受试者相比， 受试者使用眼跟踪器控制的周边观看。 我们将 确定低视力阅读能力与尺寸的关系， 中心暗点的位置和密度，以及任何发现的 周边视觉功能异常。 给一个更好的 理解周边阅读的视觉限制 性能，我们将研究新的技术，以提高或 修改图像以提高性能。 我们将 探索非线性放大和增加字母间距， 克服拥挤问题，低通空间和时间滤波 以减少横向和元对比掩蔽，并使用静态 和动态纹理来改善字母分离。

Low-vision subjects with central field loss read much more slowly than would be expected on the basis of standard clinical measures of visual function (e.g. visual acuity and contrast sensitivity). The principal goal of the proposed research program is to determine what limits reading performance in this group of subjects and to explore new techniques of Image enhancement to circumvent the visual limitations on reading in the absence of central vision. We will study reading performance in young and elderly normal observers and in low-vision subjects with central scotomas due to macular disease, primarily age-related maculopathy. To determine the limitations on reading of normal peripheral vision, normal observers will read text in the presence of an artificial scotoma stabilized on the retina with a dual-Purkinje eye tracker. Since inappropriate eye movement may severely limit peripheral reading, we will also study reading performance by presenting the text one word at a time in a fixed retinal location. This technique, known as rapid serial visual presentation, or RSVP, virtually eliminates the need for saccadic eye movements. We will determine the extent to which the peripheral retina of low vision subjects behaves like normal peripheral retina. We will measure spatial phase or position sensitivity using phase discrimination and vernier tasks. Lateral making ("crowding") effects will be investigated by measuring letter recognition in the presence or absence of flanking patterns, and metacontrast masking (backwards and forwards masking in the temporal domain) will be measured with a word recognition paradigm. Spatial undersampling will be investigated by comparing detection and orientation discrimination of grating patches, and temporal undersampling will be evaluated by comparing CFF with two- pulse discrimination. In each case we will the compare performance of low-vision subjects with central scotomas to that of normal subjects using eye-tracker controlled peripheral viewing. We will determine the relation of low-vision reading ability to the size, location, and density of central scotomas, and any discovered abnormalities of peripheral visual function. Given a better understanding of the visual limitations on peripheral reading performance, we will investigate new techniques for enhancing or modifying the image in order to improve performance. We will explore non-linear magnification and increased letter spacing to overcome crowding problems, low-pass spatial and temporal filtering to reduce lateral and metacontrast masking, and the use of static and dynamic texture to improve letter segregation.