人眼空间图形视觉的评估及其临床应用

Assessment of human vision for spatial patterns and its clinical applications

人眼对空间图形的感知取决于视觉系统对相关基本物理属性变量（包括亮度、空间频率、对比度及方向等）的信息处理.因而,对视觉行为（或视觉质量）的准确评估需要完整地测量视觉系统对这些基本变量的反应能力.由于视力测量仅反应高亮度、高对比度下视觉分辩能力,更为全面地测量视觉质量的技术,包括对比敏感度测量和对比度视力测量,已被成功地开发并广泛地应用于视觉研究与眼科临床之中.大量研究表明,不同对比度下视觉行为的测量能有效地应用于：①大部分眼科疾病的早期诊断,以及视觉干预或眼科手术效果的跟踪;②对部分眼病的特殊诊断;③视觉异常导致日常生活行为障碍的评估.另外,计算机化的视功能检测因具有可规范程度高、稳定性好、可靠性强以及测量精度高等特点,将成为应用于人眼视觉测量的必然趋势.

Human vision for spatial pattern depends on information processes in the visual system for several basic physical variables, such as luminance, spatial frequency （or size）, contrast and orientation, which determine characteristics of the pattern. Therefore, assessment of visual performance or visual quality needs to systematically measure the ability of the visual system in response to these variables. Because visual acuity only tests the resolution power under high luminance and high contrast, techniques capable of comprehensively assessing visual ability, such as the contrast sensitivity and contrast visual acuity tests, have been developed and widely applied in both eye research and clinical practice. Studies have shown that visual test under varied contrasts could be effectively used to ①diagnose many common eye diseases in the early stage and monitor effects of ophthalmic intervention and treatment; ②diagnose some specific visual disorders; and ③assess problems in daily performances which are associated with visual defects. Due to its highly standardization, and superior reliability, repeatability and accuracy in visual measurement,computerized technique will be the method for assessing visual performance in the future.