Centre for Vision and Eye Research, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Queensland, Australia.
Ophthalmic Physiol Opt. 2021 May;41(3):582-590. doi: 10.1111/opo.12811. Epub 2021 Mar 27.
Many individuals drive with uncorrected refractive errors, which has implications for night driving, where poor visibility contributes to the increased crash risk relative to daytime. This study explored how small amounts of refractive blur affects the judgment of the walking direction of night-time pedestrians and whether different types of retro-reflective clothing influence this effect.
Judgement of the walking direction of night-time pedestrians was investigated for 20 young participants with normal vision (mean age, 21.8 ± 1.6 years) for two levels of binocular blur (+0.50DS, +1.00DS) compared to baseline (best-corrected refractive correction). Participants seated in a stationary car with low beam headlamps observed a pedestrian wearing three clothing conditions: retro-reflective vest (1) and retro-reflective biomotion clothing (incorporating thin (2) or thick (3) retro-reflective strips), who walked across the road in three directions (straight across, away or towards the car). The order of conditions was randomised among participants. Participants reported the perceived pedestrian walking direction and how confident they rated their response. Outcome measures included the proportion of correct responses (response accuracy) and confidence ratings.
Blur had a significant effect on accuracy in judging pedestrian walking direction; accuracy decreased significantly with increasing blur (p < 0.001), with all blur levels being significantly different from one another. The effect of pedestrian clothing was also significant (p < 0.001); direction judgements were least accurate for vest, followed by both thin and thick biomotion, where accuracy judgements were similar. There was also a significant interaction between blur and clothing (p < 0.05). Similar trends were found for confidence ratings across the blur and clothing conditions. Greater confidence was significantly associated with increased response accuracy for the biomotion clothing, but not the vest.
Findings highlight that even small amounts of blur (+0.50DS), that do not reduce visual acuity below the legal driving limits, reduce the ability to accurately judge pedestrian walking direction at night. Retro-reflective clothing in a biomotion configuration facilitated the highest accuracy and confidence in judgment of pedestrian walking direction, for both thin and thick strips compared to vest, for all blur levels.
许多人在驾驶时存在未经矫正的屈光不正，这对夜间驾驶有影响，因为夜间能见度差会导致事故风险增加，相对于白天。本研究探讨了少量屈光模糊如何影响夜间行人行走方向的判断，以及不同类型的反光服装是否会影响这种影响。
本研究调查了 20 名视力正常的年轻参与者（平均年龄 21.8±1.6 岁）在双眼模糊（+0.50DS、+1.00DS）与基线（最佳矫正屈光矫正）相比时，对夜间行人行走方向的判断。参与者坐在装有低光束前照灯的静止汽车中，观察一名行人穿着三种服装条件：反光背心（1）和反光生物运动服装（包括薄（2）或厚（3）反光条），他们从三个方向（直接穿过马路、远离或向汽车方向）穿过马路。参与者之间的条件顺序是随机的。参与者报告了感知到的行人行走方向以及他们对自己的反应的信心程度。结果测量包括正确反应的比例（反应准确性）和置信度评分。
模糊对判断行人行走方向的准确性有显著影响；随着模糊度的增加，准确性显著降低（p<0.001），所有模糊度水平彼此之间均有显著差异。行人服装的效果也很显著（p<0.001）；背心的判断准确性最低，其次是薄和厚的生物运动服装，而准确性判断相似。模糊和服装之间也存在显著的相互作用（p<0.05）。在模糊和服装条件下，置信度评分也呈现出相似的趋势。对于生物运动服装，信心度的增加与反应准确性的增加显著相关，但对于背心则不然。
研究结果表明，即使是很小的模糊度（+0.50DS），也不会降低低于法定驾驶限制的视力，也会降低夜间准确判断行人行走方向的能力。与背心相比，在生物运动配置中使用反光服装可以在所有模糊度水平下，以最高的准确性和信心度判断行人的行走方向，无论是薄条还是厚条。
