Study On Lighting Environment Suitable For VDT Work Of The Elderly

With the rapid evelopment of Internet,the continuous improvement of education and the increasing openness of ideological level,the acceptance and dependence of the elderly on VDT(visual display terminal)products such as mobile phones,computers,TVs,i Pads,etc.are increasing year by year.While VDT products bring convenience and joy to the elderly,the visual fatigue caused by VDT work also plagues the elderly’s later life.Inappropriate lighting environment will accelerate the occurrence of VDT visual fatigue and aggravate the symptoms of visual fatigue in the elderly.Based on the social background of China’s aging society and the trend of the age of retirement may be postponed,this paper analyzes the visual fatigue of the elderly after VDT work in different lighting environments through theoretical research,investigation and experimental research,and obtains the recommended value of lighting indicators suitable for VDT work of the elderly,and then,some reasonable suggestions are put forward for the lighting design of office space suitable for VDT work of the elderly.This paper can play a positive role in preventing VDT visual fatigue and creating a healthy and comfortable VDT working environment for the elderly.Firstly,this paper analyzes the visual characteristics of the elderly through theoretical research,and points out that environmental illumination and its evenness,light source color temperature,screen brightness and contrast,color combination,glare and other factors have an important impact on VDT visual fatigue of the elderly.Then through investigation and research,it was found that computer VDT was highly used in the work and life of the elderly,and the rising trend is obvious.The elderly are most concerned about the influence of screen brightness,environmental illumination and light source color temperature.After VDT,the elderly suffered from serious visual fatigue and were most dissatisfied with the lighting environment of the office.Through the field test,it is found that the lighting design of all residences and offices does not give special consideration to the visual needs of the elderly.In general lighting,the environmental illumination,uniformity of illuminance,illuminance of working face and color temperature of light source of all residences and offices do not meet the standard recommended value.After the local lighting is increased,t the average illumination of the working face has been improved,but due to the different specifications of table lamps,the difference of grid,the illuminance and color temperature of working face of each measured space are very different.The preference of the screen brightness is very different.Based on the results of theoretical and investigation research,the office is selected as the follow-up application research object,and the office environment was simulated in the laboratory.Screen brightness,ambient illumination and color temperature of light source are selected as the experimental independent variables.According to the existing research results and lighting standards,three groups of reference values were selected for three experimental independent variables.That is to say,the reference values of screen brightness are 40cd/ ㎡,100cd/ ㎡,225cd/ ㎡,the reference values of environmental illumination are 300 lx,500lx and 750 lx,and the reference values of color temperature of light source are 3000 K,5000K and 6500 K.Two groups of simulation experiments were carried out.The first group is the experiment of environmental illumination and color temperature of light source suitable for VDT work of the elderly,the results showed that 300 lx,6500K,750 lx,6500K and 500 lx,6500K were the top three suitable lighting environments for VDT work.Based on the results of the first experiment,the second group of experiments was carried out to study the screen brightness and contrast suitable for VDT work of the elderly.The results showed that the top three lighting factors were 6500 K,500lx,40cd/㎡,6500 K,300lx,100cd/㎡and 6500 K,750lx,100cd/㎡.Finally,based on the comprehensive analysis of the theoretical,investigation and experimental research results,in order to preventing VDT fatigue of the elderly,the lighting design of office space suitable for VDT work of the elderly was studied.Through the analysis of the visual characteristics of VDT work in office space and the needs of the elderly for office space lighting,this paper puts forward suggestions for the design concept of office space lighting suitable for the elderly and the young.According to the experimental results,the specific parameters of office space environmental illumination,color temperature of light source and screen brightness are proposed as500 lx,6500k and 40cd/㎡.Then,through software simulation and comprehensive analysis,it is concluded that general lighting is the most suitable improvement measure for office lighting environment.