Effect of light source size on discomfort glare thresholds
Effect of light source size on discomfort glare thresholds
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光源尺寸对不舒适眩光阈值的影响
DOI：
10.1111/j.1755-3768.2012.4282.x
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发表时间：
2012
影响因子：
3.4
通讯作者：
JIA Y
中科院分区：
文献类型：
--
作者：
JIA Y
目的明亮的光源，如汽车前大灯或住宅路灯，会导致视觉不适。即使经过50年的多学科研究，不适眩光的起源或导致不适眩光的因素仍然知之甚少[美国眼科杂志，153(4)：587-593(2012)]。本研究考察了光源强度、大小、周围亮度和瞳孔大小对DG阈值的影响。方法实时测量瞳孔，计算视网膜照度，这是DG研究中更具针对性的参数。DG阈值的评估采用阶梯式程序：视网膜照度的增加或降低取决于参与者是否表示DG的存在或缺失。受试者被要求观看模拟居民区街道背景下呈现的光源。在计算机控制下随机选择盘源的大小。五种不同的源大小被用来在刺激面积上产生40倍的变化。结果在DG阈值下，视网膜照度基本恒定，且与光源大小无关。另一方面，瞳孔平面照度随着光源大小的增加而增加。结论这些发现表明DG主要取决于局部视网膜照度，而不是进入眼睛的总光量。因此，DG似乎在很大程度上与光感受器信号的饱和有关。结果还表明，在不增加DG的情况下，通过增加光源的大小可以获得更高水平的街道照明。
PurposeBright light sources, such as car headlamps or residential street lights, can cause visual discomfort. The origins of discomfort glare (DG) or the factors that contribute to it remain poorly understood, even after 50 years of multidisciplinary research [American Journal of Ophthalmology, 153(4):587‐593(2012)]. This study examined the effect of the light‐source intensity, size, surround luminance and pupil size on DG thresholds.MethodsThe pupil was measured in real time to calculate retinal illuminance, a more pertinent parameter in studies of DG. DG thresholds were estimated with a staircase procedure: the retinal illuminance was increased or decreased based on whether the participant indicated the absence or presence of DG, respectively. The subjects were required to view a source of light presented against a simulated residential street background. The size of the disc source was selected randomly under computer control. Five different source sizes were used to produce a 40 fold variation in stimulus area. The light source behind the aperture disc was designed to produce uniform flashes of light of varying intensity, while the surround light level remained unchanged.ResultsIt was found that at the threshold for DG, the retinal illuminance is approximately constant and independent of source size. On the other hand, pupil plane illuminance increases as source size increases.ConclusionThese findings suggest that DG depends mostly on localised retinal illuminance, rather than the total amount of light entering the eye. DG therefore appears to be largely related to saturation of photoreceptor signals. The results also suggest that higher levels of street illumination can be achieved by increasing the size of light source without causing any increase in DG.