Influence of lighting on visual performance

ABSTRACT Purpose: This review emphasizes the effect of light on visual efficiency, the impact of different lighting focuses, types of lighting, and their influence on vision and productivity. Light sources and standards are intriguing subjects for ophthalmologists. Guidelines regarding the level of lighting influence on visual activities can enhance visual performance.Methods: This article was developed based on literature reviews, with a bibliographic survey conducted in databases such as PubMed, MEDLINE, Web of Science, Embase, LILACS, and SciELO. Results: Provides recommendations for understanding information regarding the influence of lighting on visual performance. Conclusion: Proper workplace lighting is crucial for improving visual efficiency, safety, productivity, and worker health. Efficient workplace lighting should avoid light sources directed towards the worker's face, prevent harmful glare, be more intense in the work area, and uniform in the rest of the room. Ophthalmologists should be knowledgeable about and provide guidance on correct lighting to ensure patient comfort and satisfaction with visual correction.

Effects of luminous environments on visual performance of people with different vision / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To study the effects of the specific simulated luminous environment on the visual performance of people with different vision, so as to provide an experimental basis for revising pilots' vision standards. METHODS: A controlled randomized trial was conducted. Twenty-four volunteers were recruited and divided into four groups(1.0/1.0, 0.8/0.8, 0.6/0.6 and 0.4/0.4, decimal vision)according to right/left eye visual acuity, with six subjects in each group. Each subject was tested for static distant vision, kinetic visual acuity, color vision, depth perception error and visual search time under the simulated luminous environments of sunlight, twilight, and on-cloud, respectively, to compare changes in the impact of distinctive luminous surroundings on the visual performance indicators of human beings with different vision.RESULTS: There were main effect differences in static distant vision, kinetic visual acuity, color error, depth perception error and visual search time under different light environments(all P<0.01). The binocular static distant visual acuity, abilities of color discrimination, depth perception and visual search in simulated sunlight environment were higher than those in simulated twilight and on-cloud environments. In the 0.4/0.4 vision group, kinetic vision in simulated twilight and on-cloud environments were significantly lower than that in simulated sunlight environment(P<0.01). There were main effect differences in binocular static distant vision, kinetic visual acuity, depth perception error and visual search time among subjects with different vision(all P<0.05). Compared with 1.0/1.0 vision group, those with 0.6/0.6 and 0.4/0.4 vision had significant decrease in kinetic visual acuity, depth perception ability and visual search ability(all P<0.05). CONCLUSION: Different luminous environments have a great impact on the visual performance of people with low vision, which poses a potential threat to flight safety.

The effect of increasing the illumination on operators' visual performance in the control-room of a combined cycle power plant

BACKGROUND: Lighting is one of the environmental factors affecting the performance of the control room operators. Therefore, the aim of this study was to compare the control room operators’ visual performance in two different illumination conditions at a combined cycle power plant through field-work. METHODS: Sixteen operators in day shift were evaluated with the Freiburg Visual Acuity test (FrACT) software at two lighting systems with different intensities. It includes the first phase with fluorescent illumination system (Power: 40 W, Color Temperature: 4000 Kelvin, Luminous Flux: 2780 Lumen and Model: Pars Shahab) and the second phase with a combined illumination system includes fluorescent and LED (Power: 48 W, Color Temperature: 4000 Kelvin, Luminous Flux: 5400 Lumen and Model: Mazinoor). RESULTS: Based on the results, visual performance index and visual acuity significantly increased after the intervention (p < 0.001). As to contrast, more lighting significantly reduced the percentage of recognized contrast (p < 0.001) and increased the contrast performance index (p < 0.001). CONCLUSIONS: The results of this study showed that increasing the intensity of light from the values below the allowable limit to the values above the allowable limit would increase the visual indicators in individuals.

Influence of artificial luminous environment and TCM intervention on development of myopia rabbits

Objective:To explore the influence of artificial luminous environment and preventive function of traditional Chinese medicine (TCM) intervention based on “Theory of yin-yang clock” on myopia.Methods:A total of 45 New Zealand young rabbits were randomly divided into 5 groups, 9 for each group. Control group was exposed in natural light. Fluorescent group and full spectrum group were exposed in fluorescent light and full spectrum light, on which basis fluorescent TCM group and full spectrum TCM group were added with “Rizhong Yinyang Formulas”, respectively. Optical parameters were measured and the influence of different lights on the serum and retinal dopamine (DA) levels as well as the retinal histopathological tissues was observed.Results: The spectrum of fluorescent light mainly focused at 420-490 nm with the peak value of wavelength near 450 nm, whereas that of full spectrum was wider (400-800 nm) with the peak value near 600 nm. After 4 and 12 weeks, fluorescent group was evidently lower in serum and retinal DA levels (P0.05). Histopathological observation showed that there was significant difference in pigment epithelium layer, photoreceptor and nerve fiber layer between fluorescent group and control group, but the difference among the test groups was not significant.Conclusions:Fluorescent light has certain influence on retinal histological construction and visual performance. However, TCM intervention may have some degree of protective function on retina.

Influence of artificial luminous environment and TCM intervention on development of myopia rabbits

OBJECTIVE@#To explore the influence of artificial luminous environment and preventive function of traditional Chinese medicine (TCM) intervention based on "Theory of yin-yang clock" on myopia.@*METHODS@#A total of 45 New Zealand young rabbits were randomly divided into 5 groups, 9 for each group. Control group was exposed in natural light. Fluorescent group and full spectrum group were exposed in fluorescent light and full spectrum light, on which basis fluorescent TCM group and full spectrum TCM group were added with "Rizhong Yinyang Formulas", respectively. Optical parameters were measured and the influence of different lights on the serum and retinal dopamine (DA) levels as well as the retinal histopathological tissues was observed.@*RESULTS@#The spectrum of fluorescent light mainly focused at 420-490 nm with the peak value of wavelength near 450 nm, whereas that of full spectrum was wider (400-800 nm) with the peak value near 600 nm. After 4 and 12 weeks, fluorescent group was evidently lower in serum and retinal DA levels (P0.05). Histopathological observation showed that there was significant difference in pigment epithelium layer, photoreceptor and nerve fiber layer between fluorescent group and control group, but the difference among the test groups was not significant.@*CONCLUSIONS@#Fluorescent light has certain influence on retinal histological construction and visual performance. However, TCM intervention may have some degree of protective function on retina.

Influence of artificial luminous environment and TCM intervention on development of myopia rabbits

Objective: To explore the influence of artificial luminous environment and preventive function of traditional Chinese medicine (TCM) intervention based on "Theory of yin-yang clock" on myopia. Methods: A total of 45 New Zealand young rabbits were randomly divided into 5 groups, 9 for each group. Control group was exposed in natural light. Fluorescent group and full spectrum group were exposed in fluorescent light and full spectrum light, on which basis fluorescent TCM group and full spectrum TCM group were added with "Rizhong Yinyang Formulas", respectively. Optical parameters were measured and the influence of different lights on the serum and retinal dopamine (DA) levels as well as the retinal histopathological tissues was observed. Results: The spectrum of fluorescent light mainly focused at 420-490 nm with the peak value of wavelength near 450 nm, whereas that of full spectrum was wider (400-800 nm) with the peak value near 600 nm. After 4 and 12 weeks, fluorescent group was evidently lower in serum and retinal DA levels (. P0.05). Histopathological observation showed that there was significant difference in pigment epithelium layer, photoreceptor and nerve fiber layer between fluorescent group and control group, but the difference among the test groups was not significant. Conclusions: Fluorescent light has certain influence on retinal histological construction and visual performance. However, TCM intervention may have some degree of protective function on retina.

Clinical study of topography-guided off-flap Epi - LASlK in treating traumatic corneal astigmatism / 国际眼科杂志(Guoji Yanke Zazhi)

To evaluate the visual performance of the patients with traumatic corneal astigmatism, after the treatment of topography guided off-flap epipolis laser in situ keratomileusi (off-flap Epi-LASlK). ●METHODS: This prospective clinical study was comprised of 21 eyes of 21 patients with irregular corneal astigmatism caused by trauma, they were treated by off-flap Epi - LASlK from July 2012 to December 2013. The data included uncorrected visual acuity ( UCVA), best spectacle - corrected visual acuity ( BSCVA ), contrast sensitivity 1, 6mo before and after surgery; the healing area percentage of corneal epithelia, the healing time of corneal epithelia and pain score at 3d after surgery. ●RESULTS: Postoperative 1mo both UCVA and BSCVA were improved significantly than that before surgery (t =15. 703, 4. 351, P0. 05 ). Postoperative 6mo except the 3c/ d spatial frequency, the remaining 3 spatial frequency contrast sensitivity compared with those before operation were significantly improved ( P ●CONCLUSlON: Topography-guided off-flap Epi-LASlK is safe and effective in treating the patients with traumatic corneal irregular astigmatism. The operation can improve both the contrast sensitivity and the visual performance.

Functional vision barriers: a new concept analyzed in terms of human visual performance

In this work we introduce a new category of barriers that we call "functional vision barriers." This expression refers to lighting and visual elements that may complicate or hinder functional vision and may make life even more difficult for people with visual defects. These barriers appear as a consequence of certain negative effects caused by the poor design of the visual stimulus or visual environment that surrounds it in which lighting is one of the main factors. We use the term "functional vision" because this expression refers to the ability of the visual system to perform everyday tasks. We analyzed some of our previous results with regard to situations that can be considered "functional vision barriers": (1) stimuli with low luminance contrast information in which the addition of chromatic contrast improves visual performance and (2) tasks that are performed in the presence of a glare source in the visual field, diminishing visual performance and reducing brightness perception...