THE VISUAL REQUIREMENTS OF EVERYDAY TASKS

在美国，超过一百万人的视力严重受损。 他们的视觉障碍是多种多样的， 了解这些损伤如何影响日常任务的表现 比如走路和阅读。 NEI及其主办的几个研讨会 已经确定了对日常生活的视觉需求进行研究的必要性， 任务 我们试图确定视觉能力的哪些方面可以在 实验室预测移动性能。 部分正常视力 受试者将参加。 视力正常的受试者将戴上护目镜 其以各种方式限制视觉（视野限制、对比度 减少和空间频率截止）和不同程度地减少。 为所有 受试者，剩余视力将通过对比敏感度来表征 实地测量。 受试者的流动性现在正在一个 室内迷宫的泡沫橡胶柱。 容易随机化的迷宫允许 在受控条件下重复测试。 我们会做这些实验 在几个亮度。 接下来，我们将研究三个真实的 步行环境：走在大学校园里，在大自然 在一所大学的教学楼里。 目的是确定 什么样的视觉容量测量可以预测移动性能。

More than a million people in the U.S. have severely impaired vision. Their visual impairments are diverse and there is only limited understanding of how these impairments affect performance of daily tasks such as walking and reading. The NEI and several workshops sponsored by it have identified a need for research on the visual requirements of everyday tasks. We seek to determine what aspects of visual capacity can be measured in the laboratory to predict mobility performance. Partially and normally sighted subjects will participate. Normally sighted subjects will wear goggles which restrict vision in various ways (field restriction, contrast reduction, and spatial-frequency cut off) and to various degrees. For all subjects, the residual vision will be characterized by contrast sensitivity and field measurements. Mobility of the subjects is now being tested in an indoor maze of foam rubber columns. The easily randomized maze allows repeated testing under controlled conditions. We will do these experiments at several luminances. Next we will study mobility in three real pedestrian environments: walking on the university campus, on a nature trail, and in a university classroom building. The aim is to determine what measurements of visual capacity will predict mobility performance.