SUNY College of Optometry, State University of New York, New York, USA.
Ophthalmic Physiol Opt. 2011 Jan;31(1):29-32. doi: 10.1111/j.1475-1313.2010.00802.x.
Computer vision syndrome (CVS) is a complex of eye and vision problems experienced during or related to computer use. Ocular symptoms may include asthenopia, accommodative and vergence difficulties and dry eye. CVS occurs in up to 90% of computer workers, and given the almost universal use of these devices, it is important to identify whether these symptoms are specific to computer operation, or are simply a manifestation of performing a sustained near-vision task.
This study compared ocular symptoms immediately following a sustained near task. 30 young, visually-normal subjects read text aloud either from a desktop computer screen or a printed hardcopy page at a viewing distance of 50 cm for a continuous 20 min period. Identical text was used in the two sessions, which was matched for size and contrast. Target viewing angle and luminance were similar for the two conditions. Immediately following completion of the reading task, subjects completed a written questionnaire asking about their level of ocular discomfort during the task.
When comparing the computer and hardcopy conditions, significant differences in median symptom scores were reported with regard to blurred vision during the task (t = 147.0; p = 0.03) and the mean symptom score (t = 102.5; p = 0.04). In both cases, symptoms were higher during computer use.
Symptoms following sustained computer use were significantly worse than those reported after hard copy fixation under similar viewing conditions. A better understanding of the physiology underlying CVS is critical to allow more accurate diagnosis and treatment. This will allow practitioners to optimize visual comfort and efficiency during computer operation.
计算机视觉综合征（CVS）是一组在使用计算机期间或与之相关的眼部和视力问题。眼部症状可能包括视疲劳、调节和聚散困难以及干眼症。高达 90%的计算机工作者会出现 CVS，鉴于这些设备的广泛使用，重要的是要确定这些症状是否特定于计算机操作，或者只是执行持续近距视觉任务的表现。
本研究比较了持续近距任务后即刻的眼部症状。30 名年轻、视力正常的受试者在 50 厘米的观看距离下，连续 20 分钟大声朗读电脑屏幕或印刷硬拷贝页面上的文本。两种情况下使用相同的文本，大小和对比度匹配。目标视角和亮度对于两种情况相似。阅读任务完成后，受试者立即完成一份书面问卷，询问他们在任务过程中的眼部不适程度。
当比较计算机和硬拷贝条件时，报告了与任务中视力模糊（t=147.0；p=0.03）和平均症状评分（t=102.5；p=0.04）相关的中位数症状评分的显著差异。在两种情况下，使用计算机时症状更高。
与在相似观看条件下固定硬拷贝后报告的症状相比，持续使用计算机后的症状明显更差。更好地了解 CVS 的生理学基础对于更准确的诊断和治疗至关重要。这将使从业者能够在计算机操作过程中优化视觉舒适度和效率。
