The Impact of Color Rendering on Visual Fatigue in Interior Zone of Tunnel

Judicious use of lamps is of profound significance to improve the internal traffic safety of tunnels. This study evaluated the effect of LED color on human visual fatigue under mesopic vision category. According to the difference of human eyes’ response to different wavelengths of light radiation, the mesopic vision spectral luminous efficiency curve is applied to the visual fatigue evaluation methods. Taking the critical fusion frequency as the physiological index, the detection experiment of human visual fatigue was carried out in the simulated tunnel environment. The results show that spectrum with high color rendering index has a positive effect on alleviating drivers’ visual fatigue, and is more suitable for tunnel interior lighting.

CRITICAL FREQUENCY OF FLICKER MERGING AND VISUAL POTENTIALS UNDER COMPUTER LOAD

The urgency of the development and improvement of methods for studying the functional state of users of computer technology is growing in parallel with the growth of their negative impact on the main targets - visual and neuropsychic functions. Therefore, the aim of the study was to study the processes of perception of rhythmic light incentives and induced electrical activity of the visual cortex during a computer load. The study was conducted with the participation of clinically healthy students ( n = 182), who determined the critical fusion frequency of flashes and recorded rhythmic cortical evoked visual potentials during a computer-assisted visual load. To assess the nature and duration of use of computer students, as well as determining the presence and severity of computer dependency, a survey was conducted. Various types of perception of light flashes and changes in the rhythm assimilation reaction under the influence of a computer load are revealed. The data are discussed taking into account the rhythmic processes of the brain. A conclusion is drawn about the weakened, stable and strengthened types of response of oscillatory neural mechanisms to computer visual loads.

Neurobehavioral Effects of β-Escin

Background: Aescin or β-escin is the main and active constituent of horse chestnut seed (Aesculus hippocastanum) used for the treatment of inflammatory edema, venous insufficiency and ischemic ulcerations. Aescin has many actions due to induction of endothelial nitric oxide and prostaglandin F2-α production moreover; aescin antagonizes the effect of histamine and 5HT at receptor levels. </P><P> Objective: The aim of the present study was to evaluate the neurobehavioral effects of aescin on normal healthy volunteers. </P><P> Method: A total number of 65 healthy participants with mean age of 21+1.1 years were recruited to study the effects of aescin on the neurobehavioral effects of normal healthy volunteers compared to placebo. The neurobehavioral effects were assessed by psychomotor performances and sensorimotor reaction, cortical arousal and central integrity processes and assessment of memory capacity. Results: Placebo produced insignificant amelioration of TRT and RRT p>0.05, with mild significant effect on MRT p=0.03. Aescin produced a significant effect in the amelioration of psychomotor performances and sensorimotor reaction p=0.0001. Regarding the differential effect of placebo and aescin on the cortical arousal and central integrity processes, placebo illustrated insignificant effect at p>0.05 whereas; aescin showed mild significant effect on Critical Fusion Frequency (CFFA) p<0.05 and highly significant effect on the other parameters p<0.01 except for critical-fusion frequency threshold when aescin illustrated insignificant effect at p>0.05. Aescin illustrated significant acceleration of ІІ-back WMA, ІІІ-back WMA and Second trial Short-Term Memory (STM) at p<0.01 compared to the placebo effect. Conclusion: Short-term therapy with aescin improves the neurobehavioral effects on healthy volunteers.

Visual Fatigue Caused by Tablet PC Based on Critical Fusion Frequency and Eye Blink Frequency

The objective of the study is to evaluate visual fatigue induced by different tablet PCs (LCD/OLED) by measuring CFF (critical fusion frequency), BF (eye blink frequency) and (SR) subjective rating. Twelve healthy subjects (10 males and 2 females) participated in the study in a controlled simulated living environment with a 18-23°C temperature, 30-45% relative humidity and 150lx illuminance. The experiment was carried out about 50 minutes, including: 30 minutes watching task (EOG test) and 20 minutes test (including subjective questionnaire and CFF test before and after the experiment). The experiment design included dependent variables: CFF, BF and subjective rating (SR); and two independent variables: Tablet PC types, watching times. As a result, after the experiment, the decline range of CFF of LCD was lower significant than that of OLED (p<0.001); the decline range of BF of LCD was higher than that of OLED (p<0.01). Also, subjective rating indicated a consistent result that higher visual fatigue was founded after watching LCD. As a whole, watching LCD tablet PC caused higher visual fatigue than watching OLED tablet PC in general.