未来人工照明:向阳光靠近——人工智能照明与视觉健康

光对于人眼的正常发育和视觉形成起到了至关重要的作用.人工照明所形成的人类新环境是现代社会发展的必然,而涉及眼健康或眼损伤的环境关联因素之一也是人工照明.在未来人工智能照明的科技发展中,如何寻求适宜眼健康的科技方向?综合光与视觉的科学研究和诸多分析观点,作者提出,未来的人工智能照明应该向"阳光"靠近,合理构建光谱组成、模拟自然光节律,并实现可调节化.     

Psychophysical measurement of spectral sensitivity and color vision in red-light-reared tree shrews (Tupaia belangeri).

The role of the spectral lighting environment on the post-natal development of spectral sensitivity and color vision was studied in tree shrews (Tupaia belangeri) that were born and reared to adulthood in cyclic red light. Normal tree shrews are dichromats, possessing short-wavelength-sensitive (SWS) and long-wavelength-sensitive (LWS) cone receptors and a small population of rods. Red-light-rearing (RLR) produced differential stimulation of the cone types by effectively eliminating photic stimulation of the SWS cones, without depriving the LWS cones. Spectral sensitivity and color vision were measured behaviorally for RLR shrews and normal shrews under different ambient light levels. Spectral sensitivity functions were deutan-like, exhibiting maxima at ca 450 and 550 nm and a minimum at 510 nm. No significant differences in spectral sensitivity were observed between RLR and control animals. Furthermore, all animals demonstrated deutan-type dichromatic color vision evidenced by their ability to discriminate monochromatic lights from equally-bright achromatic lights except for a "neutral point" near 505 nm. These results demonstrate that a population of functional SWS cones survived the lack of post-natal photic stimulation. However, RLR shrews differed from controls in that they were poorer at making chromatic/achromatic discriminations. While no severe disorganization of color vision was evident, the poorer discrimination displayed by the RLR animals is likely the result of changes in post-receptoral visual mechanisms.     

The validity of the University of Waterloo Colored Dot Test for Color Vision Testing in adults and preschool children.

PURPOSE: Most color vision tests require a high level of cognitive ability and as such are problematic for preschool children and multiply challenged individuals. Our goal was to design a color vision test for these groups and evaluate the clinical utility for preschool children. METHODS: The University of Waterloo Colored Dot Test (UWCDot) for Color Vision Testing requires the subject to distinguish a colored disc from seven gray discs. The target disc was a Munsell color along the deutan, protan, or tritan confusion line with gray. The first phase estimated the sensitivity and specificity of the test for adults. Thirty-one adults with normal color vision and 21 adults with congenital red-green defects participated. In the second phase, the utility of the UWCDot test for screening preschool children was determined. Subjects were 281 males and 269 females aged 2.5 to 5 years with normal vision. Their color vision was also assessed with the Standard Pseudoisochromatic Plates, Part 1 (SPP1). RESULTS: The sensitivity and specificity of UWCDot for adults approached the values for the desaturated D-15 when subjective responses were scored. Monitoring fixational eye movements produced sensitivity and specificity values that were similar to the anomaloscope. After adjusting the scoring criterion for the preschool children by using the females as a control, 2.9% of the males were identified as red-green deficient, 1.8% were blue-yellow deficient, and 3.2% had an unclassified deficiency. By definition, 1% of the females failed the test. Counting fixational eye movements was not a useful scoring method in the preschool children. Comparisons with SPP1 indicated that the UWCDot uncovers approximately 35% of the individuals with definite red-green color vision defects. CONCLUSIONS: Our results indicate that the UWCDot is capable of detecting approximately 35% of the preschool children who have a congenital red-green color vision defect. These individuals are likely to have a more severe deficiency.     

Color vision testing in an area with high levels of ambient illumination

This study evaluated the color discrimination of adults who were exposed to long durations of sunlight during their lifetime. The Farnsworth-Munsell 100-Hue test was used to examine the color vision of 141 subjects (mean age, 46.5 years), who had no ocular diseases and whose visual acuities ranged from 20/40 to 20/16. Results showed higher total error scores than previously published norms. There was a tendency for blue-yellow axis, especially in men older than 45 years. Long exposures of ambient light may cause color vision deficiencies.     

Advances in understanding the molecular basis of the first steps in color vision

Serving as one of our primary environmental inputs, vision is the most sophisticated sensory system in humans. Here, we present recent findings derived from energetics, genetics and physiology that provide a more advanced understanding of color perception in mammals. Energetics of cis–trans isomerization of 11-cis-retinal accounts for color perception in the narrow region of the electromagnetic spectrum and how human eyes can absorb light in the near infrared (IR) range. Structural homology models of visual pigments reveal complex interactions of the protein moieties with the light sensitive chromophore 11-cis-retinal and that certain color blinding mutations impair secondary structural elements of these G protein-coupled receptors (GPCRs). Finally, we identify unsolved critical aspects of color tuning that require future investigation.     

Congenital large field color vision defects

To investigate changes in the way of seeing colors due to expansion of the visual angle in patients with congenital color vision defects, an anomaloscope which can alter the visual angle to 2 degrees, 6 degrees, 10 degrees, 15 degrees and 20 degrees was prepared using three colored light emission diodes, and 28 patients with congenital color vision defects were examined. The results showed that the patients could be categorized into two groups: one with no change in the equation range and one in which the equation range was contracted. Contraction of the equation range was marked when the visual angle was 10 degrees or more.     

Color defective drivers and safety.

At least seven million drivers in North American cannot reliably identify red and green lights. The common assumption by traffic authorities that no serious problems exist is contradicted by the data on color vision, the testimonies of color defective drivers, studies under controlled conditions, and by reliable accident statistics. Color defective drivers can be provided with the same measure of traffic light safety as for normals. Brake lights on vehicles can be made equally effective for color defectives. Suggestions are provided to help those with color defective vision to compensate for their problems.     

Ultraviolet radiation as a risk factor for cataract and macular degeneration

The human eye is constantly exposed to sunlight and artificial lighting. Light transmission through the eye is fundamental to its unique biological functions of directing vision and circadian rhythm, and therefore, light absorbed by the eye must be benign. However, exposure to the intense ambient radiation can pose a hazard particularly if the recipient is over 40 years of age. This radiation exposure can lead to impaired vision and transient or permanent blindness.Both ultraviolet-A (UV-A) and UV-B induce cataract formation and are not necessary for sight. Ultraviolet radiation is also a risk factor for damage to the retinas of children. The removal of these wavelengths from ocular exposure will greatly reduce the risk of early cataract and retinal damage. One way this may be easily done is by wearing sunglasses that block wavelengths below 400 nm (marked 400 on the glasses). However, because of the geometry of the eye, these glasses must be wraparound sunglasses to prevent reflective UV radiation from reaching the eye. Additional protection may be offered by contact lenses that absorb significant amounts of UV radiation.In addition to UV radiation, short blue visible light (400-440 nm) is a risk factor for the adult human retina. This wavelength of light is not essential for sight and not necessary for a circadian rhythm response. For those over 50 years old, it would be of value to remove these wavelengths of light with specially designed sunglasses or contact lenses to reduce the risk of age-related macular degeneration.     

色盲矫正研究现状

色盲是一种常见的视觉异常或缺失的疾病,通常为遗传因素所致。而色盲患者由于辨色能力不同程度地缺失,影响生活和工作。目前色盲光学矫正、基因治疗恢复三原色视觉功能的治疗效果尚需验证。计算机视觉科学及人工智能的发展将其应用于色盲矫正成为新方法。现就目前关于各种色盲的治疗与矫正方法作一综述,使眼科医师和计算机工程技术人员对其有更...     

Autosomal dominantly inherited macular dystrophy with preferential short-wavelength sensitive cone involvement

We found an apparently inherited tritan-like color vision defect in five members of a family, spanning three generations. The defect was associated with mild macular pigmentary changes, poor foveolar reflexes, or slightly reduced visual acuity in four of the affected individuals. The inheritance pattern appeared to be autosomal dominant. Results of various color vision tests indicated preferential involvement of the short-wavelength sensitive cone system, with relative preservation of the middle- and long-wavelength sensitive cone systems. Both anomaloscope testing with larger (8-degree) fields and short-wavelength sensitive electroretinography indicated some short-wavelength sensitive cone system involvement beyond the central macula in the three affected individuals on whom testing was performed. The condition appeared to be a familial macular dystrophy with preferential short-wavelength sensitive cone involvement. The abnormal macular findings and mild reduction in visual acuity distinguish this condition from congenital tritanopia; the normal optic disks distinguish it from autosomal dominant optic atrophy.     

Performance of air traffic control tasks by protanopic color defectives

Air traffic controllers perform a number of tasks which involve color identification, color discrimination, and color naming. Normal color vision is required for air traffic controllers, although the requirement is currently under review. The most critical task involving color is the distinction of red and black on flight strips; the distinction must be made reliably, quickly, and routinely for flight safety. In this study of four protanopes and three normals, all the protanopes were unable to make this distinction reliably under the lighting levels encountered at air traffic control (ATC) centers, whereas none of the normals had any difficulty. Protanopes also made numerous errors with other ATC tasks involving color. The use of a red filter, often recommended to aid color defectives, actually made performance worse and additionally compounded the usual protanopic loss of brightness for red light. When Snellen visual acuity was tested using the red filters, protanopes needed up to four times larger letters than the color normals. It is concluded that protanopes have inadequate vision for safe performance of some current ATC tasks.     

Two temporal phases, brightness-dependent and -independent, in the chromatic response elicited by a briefly-flashed monochromatic light: a preliminary report

The strength of chromatic response elicited by a briefly-flashed monochromatic light, which varied in its exposure duration, was measured with the "transient cancellation method" in Experiment 1. It was found that the chromatic response of a test color depended on brightness of the test field, up to the exposures of 100-200 msec. But it began to decrease, independent of brightness of the field, at the longer durations. The above results were confirmed by Experiment 2, in which the perceived saturation of a colored light was estimated with the two alternative forced choice method. Those results were tentatively interpreted as indicating the two kinds of chromatic responses presumably originating at the different stages in the visual system. Some other psychophysical dada on color vision were briefly referred to in relation to the present results.     

Development of visual sensitivity to light and color vision in human infants: a critical review

The recent literature on test threshold and color vision in human infants is critically reviewed. Test thresholds are higher in infants than in adults at the absolute threshold and at all adapting luminances, but approach adult values rapidly over the first six months of life. The spectral luminous efficiency function of infants is similar to V(lambda) above 1.0 log phot. cd/m2. For lights below about 1.0 log scot. cd/m2 and wavelengths shorter than 590 nm, the luminous efficiency function is similar to V'(lambda). The luminous efficiency of any given stimulus may differ markedly between infants and adults, especially when the adult data depend on the temporal and spatial parameters of the stimuli. Color vision improves greatly over the first three postnatal months, and most normal 3-month olds have at least some color vision. The overall insensitivity of infants to contrast is likely to provide a satisfactory explanation of the poor color vision of infants. The critical immaturity primarily responsible for the high thresholds and poor color vision of infants is probably after the site of visual adaptation, although lower-level factors may also play a role.     

不同光环境下哈萨克族人视力调查

目的:探讨光环境改变对人眼屈光状态的影响。方法:2005-11/2006-11随机调查哈萨克族人427例828眼,年龄40～60岁,其中牧区哈萨克族人279例546眼,主要以自然光为主要照明方式,城市哈萨克居民148例282眼,以人工光源为主要照明方式,且光照时间延长,对调查对象进行裸眼视力检查和屈光状态检查等。结果:城市哈萨克族人裸眼视力19.1%(54眼)为0.4～0.5,20.9%(59眼)为0.6～0.8,17.7%(50眼)为1.0以上者。而牧区哈萨克族人裸眼视力25.1%(137眼)为0.6～0.8,58.4%(319眼)在1.0以上。两组人群裸眼视力≥1.0者,人群分布有显著性差异。城市哈萨克族人屈光度多分布在平光和-4.0之间,而牧区哈萨克族人屈光度多分布在+2.00D～-2.00D之间,两组人群屈光度为+2.00D～平光和≤-3.00D以上者,人群分布有显著性差异。城市哈萨克族人日光灯为主要的照明光源,70.9%(105例)人工光源照射超过6h。牧区哈萨克族人主要在室外活动,以自然界全光谱自然光照明为主,75.3%(210例)户外活动时间超过9h以上。结论:光环境的变化可能是引起近视发病率增高的重要因素。     

Red light increment threshold as a measure of deficient color vision.

PURPOSE: People with deficient red/green color vision have both poor color discrimination and are also insensitive to colored lights, especially red, in an increment threshold situation. In this study we compare detection thresholds for a long wavelength increment to two standard color discrimination tests. METHODS: Forty-five color normal subjects and 19 color-deficient subjects (CDs) (12 deutans, 4 protans, and 3 unclassified) were tested with the Hardy-Rand-Rittler (HRR) plate test (4th edition), Farnsworth D-15 arrangement test and a long wavelength increment threshold test, i.e., the red test. RESULTS: All CDs were less sensitive to the red increment than any of the normal subjects. The red test identified all CDs. There were no significant correlations between the red test results and the HRR test or the Farnsworth D-15 test. CONCLUSIONS: The red test measures red light increment threshold, a characteristic of color vision not assessed by conventional tests of color vision which are based upon measuring loss of color discrimination. All CD observers have raised red light increment thresholds and the test clearly differentiates CD observers from those with normal color vision.     

A computer-controlled color vision test for children based on the Cambridge Colour Test

The present study aimed at providing conditions for the assessment of color discrimination in children using a modified version of the Cambridge Colour Test (CCT, Cambridge Research Systems Ltd., Rochester, UK). Since the task of indicating the gap of the Landolt C used in that test proved counterintuitive and/or difficult for young children to understand, we changed the target stimulus to a patch of color approximately the size of the Landolt C gap (about 7 degrees of visual angle at 50 cm from the monitor). The modifications were performed for the CCT Trivector test which measures color discrimination for the protan, deutan and tritan confusion lines. Experiment 1 sought to evaluate the correspondence between the CCT and the child-friendly adaptation with adult subjects (n = 29) with normal color vision. Results showed good agreement between the two test versions. Experiment 2 tested the child-friendly software with children 2 to 7 years old (n = 25) using operant training techniques for establishing and maintaining the subjects' performance. Color discrimination thresholds were progressively lower as age increased within the age range tested (2 to 30 years old), and the data--including those obtained for children--fell within the range of thresholds previously obtained for adults with the CCT. The protan and deutan thresholds were consistently lower than tritan thresholds, a pattern repeatedly observed in adults tested with the CCT. The results demonstrate that the test is fit for assessment of color discrimination in young children and may be a useful tool for the establishment of color vision thresholds during development.     

Aircraft accidents and incidents associated with visual effects from bright light exposures during low-light flight operations.

INTRODUCTION: Preservation of optimal night vision is important for pilots operating aircraft in low-light conditions. This study investigates operational problems experienced by civilian airmen exposed to bright light sources while performing nighttime aviation activities. METHODS: The National Transportation Safety Board (NTSB) Aviation Accident and Incident Data System and the Federal Aviation Administration (FAA) Accident/Incident Data System were queried using terms associated with night vision problems. Accident and incident reports annotated with 1 or more of these terms were reviewed to determine whether exposure to bright lights at night may have contributed to the mishap. RESULTS: Vision problems resulting from exposure to bright lights at night contributed to 58 mishaps. Reports included 30 (NTSB) accidents and 28 (FAA/NTSB) incidents. The majority of accidents (57%) occurred during the approach and landing phase of flight. Incidents occurred most frequently while taxiing (54%) and during approach and landing (36%). CONCLUSIONS: Exposure to bright light sources at night has contributed to aviation accidents and incidents. The information in this study may assist airport authorities in identifying and eliminating hazardous lighting near flight paths and surface movement areas. Preventive measures for avoiding conditions that compromise the safety of aviation operations at night are discussed.     

Light filters to improve vision.

Visual impairment not only derives from deficient processes within the ocular tissues, but also from the quality and quantity of environmental lighting. High levels of short wavelength light are not used efficiently in eyes that have cloudy media anterior to the retina or whose cones are deficient. Chromatic aberration, light scattering, and fluorescence are enhanced by short wavelength lighting. We show here that in human vision and in photography, elimination of environmental light with wavelengths shorter than 450 nm improves both contrast and visual clarity, especially through cloudy media. Cutoff filters with appropriate characteristics could be developed to improve vision in elderly and visually impaired people whose ocular media mishandle short wavelength light.