Study On The Influence Of Glare On Drivers' Visual Works At Night

The functional influence of glare on visual work is mainly caused by that the beam of light goes into man's eyes, scatters in refracting media and forms equivalent veiling luminance which reduces luminance contrast of object and background to a certain degree. Because glare is one of the important factors affecting traffic safety on roads at night, and the all-round and quantitative research about the influence of glare on visual function is somewhat poor and insufficient, so this paper puts the main emphasis on the research of"the method of quantitatively analyzing influence of glare on drivers'visual work on roads at night", the researching content includes measurement of parameters about glare and quantitative analysis on these parameters.In the aspects of measurement, this paper analyses the problems of existing measures and provides a method of measure with digital camera. On the base of research in the past about measuring low luminance with DC, this paper overcomes the restriction of DC's latitude and finds the method of measuring high luminance with DC, gets a perfect computational formula.In the aspects of quantitative analysis, in order to make the research more convenient, the"visual work of driving at night"is broken down into three divisions of visual work: Can it be seen (contrast threshold)? What is it (recognition threshold)? How quickly (reaction time)? After some experiments, this paper finds out the law of influence of glare on these three division works: the glare is favorable to contrast threshold and reaction time when it's weak, and unfavorable to them when it's strong; To recognition threshold , the glare is always unfavorable. Also, the paper gets a new function about the relationship between the logarithms of equivalent veiling luminance caused by glare and contrast threshold, reaction time: ,and a new function about the relationship between the equivalent veiling luminance and contrast threshold: .In the research about glare, we call the glare which affects visual function by equivalent veiling luminance"Disability Glare", as the word suggests, the equivalent veiling luminance caused by glare is usually considered unfavorable to part or all function of vision. This is not in agreement in total with the results of the experiment, so at last, the paper does some theoretical analyses on this situation and gives relating explanation.