对比敏感度、视锐度与目标识别的相关性研究

Correlative Study of Contrast Sensitivity and Visual Acuity in Identification of Target

对12名视力正常受试者的常规视力、5个对比水平处(92％、52％、30％、22％和11％)的对比视力和7个空间频率处(0.5、1.0、1.8、3.7、9.2、29.1和43.6 cpd)的对比敏感度以及他们对3种视角(30′、20′、10′)不同对比度的飞机、登舰降落圈、“C”字符号图形的辨认正确率进行测量。测量数据输入微机行多元相关分析。结果显示:常规视力与上述图形辨认无相关性;对比视力与2个图形辨认(20′视角的降落圈,10′视角的“C”字符)有显著相关;对比敏感度函数与飞机、降落圈和10′视角“C”字符图形辨认有显著相关。结果提示,把对比敏感度函数作为预示识别低对比和较大目标的能力有意义;但作为人员筛选指标的具体使用还需进一步探讨。

The measurements of binocular CS at 7 spatial frequencies (0. 5, 1. 0, 1. 8, 3. 7, 9. 2, 29. 1 and 43. 6 cpd), Snellen acuity, Landolt 'C' visual acuity (MCVA) at 5 contrast levels (92%, 52%, 30%, 22% and 11%) and the efficiency of identifying 3 kinds of target projections (air-craft, landing mark, landolt 'C' in 12 subjects with 6/6 (20/20) or better visual acuity were made. The results showed that there were no correlative relation between the target identification efficiency or all kinds and Snellen acuity, but there were significantly correlative relations between the target identification efficiency of some kinds and MCVA. However, the target identification is significantly correlated with CSF (P<0. 05). This pa- per proved that CSF is more sensitive than acuity. It is suggested that CSF may be used to predict target identification performance in the complex visual task.