Kuyk T, Elliott J L, Fuhr P S
The Department of Veterans Affairs Medical Center, The University of Alabama at Birmigham, 35233, USA.
Optom Vis Sci. 1998 Jul;75(7):538-47. doi: 10.1097/00006324-199807000-00023.
To determine the effects of reducing light level from photopic to mesopic on performance of real world mobility tasks and how performance of these tasks relates to measures of visual sensory and perceptual function.
The visual functions, acuity, peak letter contrast sensitivity, visual field extent, glare disability, color confusion, motion sensitivity, spatio-temporal contrast sensitivity, scanning ability, and figure-ground discrimination were measured to determine their ability to predict mobility performance of visually impaired adults on indoor hallway and outdoor residential travel routes under photopic and mesopic lighting conditions.
Time to complete routes and number of mobility incidents were significantly increased under mesopic conditions. Depending on the task, lighting conditions, and performance measure, predictive models consisting of 4 vision variables were able to account for 30 to 42% of the variance in overall performance. The two most important variables in these models were visual field extent and scanning ability, followed by color confusion, grating contrast sensitivity, or spatial resolution.
Reducing illumination levels from photopic to mesopic has an adverse effect upon mobility in older visually impaired adults. The aspects of vision which best predict performance include measures of sensory and perceptual visual function. The results compare well with those obtained under controlled laboratory conditions.
确定将光照水平从明视觉降低到中间视觉对现实世界中移动任务表现的影响，以及这些任务的表现与视觉感觉和感知功能测量指标之间的关系。
测量视觉功能、视力、峰值字母对比敏感度、视野范围、眩光残疾、颜色混淆、运动敏感度、时空对比敏感度、扫描能力以及图形-背景辨别能力，以确定它们在明视觉和中间视觉照明条件下预测视力受损成年人在室内走廊和室外住宅行进路线上移动表现的能力。
在中间视觉条件下，完成路线的时间和移动事件的数量显著增加。根据任务、照明条件和表现测量指标，由4个视觉变量组成的预测模型能够解释总体表现中30%至42%的方差。这些模型中两个最重要的变量是视野范围和扫描能力，其次是颜色混淆、光栅对比敏感度或空间分辨率。
将光照水平从明视觉降低到中间视觉对老年视力受损成年人的移动有不利影响。最能预测表现的视觉方面包括视觉感觉和感知功能的测量指标。结果与在受控实验室条件下获得的结果相当。
