Visual capacities of the owl monkey (Aotus trivirgatus)--II. Spatial contrast sensitivity.

Spatial contrast sensitivity functions were measured for the owl monkey (Aotus trivirgatus) in a forced-choice discrimination task in which the animals discriminated sinusoidal luminance gratings variant in contrast from homogeneous fields of the same average luminance. At photopic light levels theAotus monkey is maximally sensitive to gratings having a spatial frequency of 1.5–2.0 c/deg. As target luminance was decreased, both the peak location and the form of the function changed. From a consideration of these functions, and from measurements of square-wave grating acuity, it was con cluded that the maximal resolution for theAotus monkey is about 10 c/deg. In comparison to the human observer, this monkey shows poorer spatial resolution at moderate light levels but better resolution when the target is very dim.     

百分制色觉定量检测表对正常人及先天性色觉异常者色觉感色力及辨色力的评估

目的 通过自行设计百分制色觉定量检测表(百分制量表)检查正常人及先天性色觉异常者色觉感色力和辨色力的差异。设计诊断技术评价。研究对象 采用俞自萍色盲本筛查色觉正常者48例(男性46例,女性2例);采用Farnsworth Munsell(FM-100)色相检测法确诊的红色觉异常者28例(男性27例,女性1例),绿色觉异常者71例(男性68例,女性3例)。方法 采用自制百分制量表检测受试者的色觉感色力和辨色力,并对评分进行对比分析,采用中位数(四分位数)描述。主要指标红色、绿色及蓝色感色力和红绿、红蓝及绿蓝辨色力百分制量表评分。结果 用百分制量表评价,正常人红色、绿色、蓝色感色力评分分别为96(95,97)、98(97,98)、95(92.25,96);红绿、红蓝、绿蓝辨色力评分分别为97(97,98)、96(95,97)、98(97,98)。与正常人相比,先天性红色觉异常患者的红色感色力[91.5(89.25,93)]、蓝色感色力[93(90,95)]和红蓝辨色力[90.50(86.25,92)]评分下降(Z=-6.837、-3.151、-6.780,P均<0.01);先天性绿色...     

黄色人工晶状体植入对比敏感度和色觉的研究

目的 研究黄色人工晶状体（ＩＯＬ）植入眼内主观感觉、对比敏感度和色觉的变化。方法老年白内障６０人（６６眼）,随机分成两组,植入黄色ＩＯＬ３０眼,普通ＰＭＭＡＩＯＬ３６眼。术后１周,１,３,６月时,分别询问主观感觉、测量视力对比敏感度、色觉。结果 黄色ＩＯＬ比普通ＰＭＭＡ ＩＯＬ在空间对比敏感度的低、中频率上显著长春市,主观感觉也较好。结论 黄色ＩＯＬ比普通ＰＭＭＡＩＯＬ在空间对比敏感度的低、中频率     

Psychophysical studies of pigeon color vision—I. Photopic spectral sensitivity

A two-choice operant discrimination procedure was used to determine the spectral sensitivity function for the red field of the pigeon visual system under light adaptation. The data are consistent with a proposed model of the visual system which assumes that spectral sensitivity is determined by an additive combination of responses from cones containing the 562 pigment, and cones containing a postulated pigment with a peak absorption at 415 nm.     

Changes of color vision in ocular hypertension

Fifty-six ocular hypertension (OHT) patients were examined for 2–3 days in the Eye Clinic of Kuopio University Hospital. No glaucomatous changes were found. Twenty-seven of them were found to have several risk factors for developing glaucoma and medication was started. Twenty-nine of the patients did not show risk factors and had no medication. Color vision was examined with the Farnsworth-Munsell 100 (FM 100) hue test and Besançon anomalometer, later Color Vision Meter 712 at the beginning of the study and 3 years later.None of the 56 patients showed any glaucomatous changes after 3 years of the study. In the treatment group, the FM 100 test showed significantly (paired t-test, p=0.004) improved error scores after 3 years. In the nontreatment group, 19 patients did not develop risk factors; they had no significant changes in the color vision results. In 10 patients of the non-treatment group, risk factors had developed with elevated intraocular pressure and medication was started for them after 3 years. Their color vision results in the blue anomalous quotient (AQ) of the anomalometer had significantly shifted to the blue part of the equation (paired t-test, p=0.04). The other color vision results had not changed significantly.The significantly improved FM 100 scores in the treatment group could mean, that the treatment has a beneficial effect for the OHT eyes at risk for developing glaucoma. The significant shifting of the blue AQ towards the blue part of the equation in the eyes with elevated pressure after 3 years could mean that minimal change in blue color vision measured by a blue anomaloscope might be a risk factor for glaucoma development.Abbreviations AQ anomalous quotient - FM-100 Farnsworth-Munsell 100 hue test - IOP intraocular pressure - MMP mid matching point - MR matching range - NS not significant - OHT ocular hypertension - S significant - SD standard deviation     

视觉评估领域的SLCT和锥细胞对比敏感度测试的临床应用分析

目的：描述新的对比敏感度及色觉检查的原理及其临床应用。方法：对比敏感度用SLCR来评估。SLCT是由几行大小不变(20／25)，但对比度逐渐降低的字母组成的对比敏感度表。色觉以锥细胞的对比敏感度来评估，这是一种视屏测试方法，每一个字母都代表三种视锥细胞中的一种类型(红、绿或蓝)，对比度逐渐降低，分别确定分辨的阈值。测试对象分别为正常受试者以及有眼部疾病的患者。结果：SLCT在检查微小的离焦量以及早期眼部疾病方面比传统的检查具有更大的优势。锥细胞对比敏感度测试比传统的色觉检查敏感性高，不仅可以揭示遗传性色觉异常的类型及其严重程度，而且可以发现不同疾病造成的敏感度的下降。结论：这些新的方法拓展了视觉评估领域，揭示了人眼分辨力的微小变化，提示了遗传性、获得色觉异常眼病的类型和严重程度。     

Observations on color vision testing in ocular hypertension and glaucoma

Forty-eight patients aged from 60 to 69 years (58 eyes) with ocular hypertension (OHT) or primary open angle glaucoma (POAG) and a control group of 16 persons (31 eyes) were studied with six color vision tests: Standard Pseudoisochromatic Plates Part 2, Farnsworth Panel D 15, Farnsworth-Munsell 100-hue (FM 100) test, Lanthony Desaturated Panel, Nagel (red-green) anomaloscope, and Besançon (blue) anomalometer. In the color vision tests, the newly diagnosed OHT eyes without treatment differed significantly from the control group in the blue anomalometer. The long-term OHT eyes with treatment had no significant difference from the normals in any of the tests. The newly diagnosed POAG eyes without treatment were significantly different from the normals in the FM 100 test as well as in the boxes I, II, III and IV of the test, in the Lanthony Desaturated Panel and in the blue anomalometer. The long-term POAG eyes with treatment only differed significantly from the normal eyes in the blue anomalometer. The box IV of the FM 100 test and blue anomalometer were observed to be the most useful of these six tests in finding the possible early beginning of the blue color vision defect in the group of newly diagnosed OHT.Abbreviations AQ anomalous quotient - FM 100 Farnsworth-Munsell 100 hue test - IOP intraocular pressure - MR matching range - OHT ocular hypertension - POAG primary open angle glaucoma - SD standard deviation - SPP2 Standard Pseudoisochromatic Plates part 2     

Visual pigments and colour vision in a nocturnal bird, Strix aluco (tawny owl)

Microspectrophotometer measurements of the oil droplets and visual pigments in the receptors of the tawny owl (Strix aluco) have demonstrated the presence of at least four types of oil droplets and three visual pigments. The majority of cones contain a pale yellow droplet and a yellow-absorbing visual pigment withλ_max 555 nm. Two further types of cone can be recognised containing either a green-absorbing pigment,λ_max 503 nm, or a blue-absorbing pigment,λ_max about 463 nm. A fourth type of cone containing a red oil droplet was also identified. The rods contain a P503, similar in absorbance to the green-absorbing cone visual pigment. From the transmission characteristics of the oil droplets and the absorbance spectra of the cone visual pigments, the effective spectral sensitivities of each cone type have been derived. These photopic mechanisms are discussed in relation to psychophysically-determined photopic sensitivities of the tawny owl and to the photopic systems of two diurnal birds.     

Structural and functional correlates in color vision deficiency

Purpose

The aim of this study is to assess the photoreceptor integrity, using spectral domain optical coherence tomography (SD-OCT), and to measure the retinal sensitivity of patients with congenital red–green color vision deficiency (CVD).

Methods

In all, 14 eyes from 7 patients with congenital red–green CVD (diagnosed by Farnsworth Munsell 100 hue test), and 14 eyes from 7 control subjects were examined by SD-OCT and microperimetry. Radial scans (7-mm) were taken of the macula. The center of the fovea was defined. The thickness of different retinal layers, at the foveal center, and at multiple defined points along all six radial scans, was measured. The median readings were compared between the two groups using Mann–Whitney U-test.

Results

SD-OCT demonstrated normal total retinal thickness, normal thickness of the photoreceptor layer, normal thickness of the outer nuclear layer, normal vertical thickness of the outer segments (OSs), and normal vertical thickness of the inner segments. OS horizontal diameter was less in left eye in cases with CVD when compared with controls. The mean retinal and foveal sensitivity was similar between cases and controls.

Conclusions

In subjects with congenital red–green CVD, there are no discernible anatomical abnormalities seen on SD-OCT in various retinal layers, except for a narrower foveal pit. However, further studies with larger sample size are required.     

正常及先天性色觉异常者颜色视觉诱发电位的研究

目的　了解颜色刺激正常人和色觉异常者不同记录部位的VEP表现,作临床功能判断和色觉机制分析的参考。方法　通过实验用计算机软件控制亮度和颜色因素,用黑-白棋盘格和等亮度的红-白、绿-白及红-绿颜色棋盘格作为刺激模式,记录一组正常人及色觉异常者的瞬态诱发电位。结果　(1)正常人在红-白、绿-白及红-绿刺激下,10导联P1波振幅低,在红-白、绿-白刺激下,15导联P1波潜伏期长,结果比较具有统计学意义。(2)正常人在上述四种刺激条件下P1波潜伏期按时间长短顺序,红-白＜黑-白＜红-绿＜绿-白,潜伏期之间的比较具高度显著性;P1波振幅的高低是黑-白＞红-白、红-绿、绿-白,差异有显著性,但颜色刺激之间振幅的比较无差异。(3)色觉异常组在四种刺激每件下P1波潜伏期长短及振幅的高低之间无差异,但黑-白刺激潜伏期最短。红绿色盲及绿色盲,对绿-白刺激无反应,对红-白及红-绿有反应,但振幅较正常人显著降低。(4)正常组与色觉异常组P1波的比较,潜伏期无差异,振幅在黑-白刺激下无差异,在颜色刺激下,差异有显著性。结论　(1)颜色视觉诱发电位客观地检查先天性色觉异常是可行的,对红绿色盲和绿色盲尤为敏感。(2)在视中枢内可能有一个相对主要的颜色区域。(3)颜色和亮度的处理似同在一个视觉系统,均由小细胞神经节细胞传导。(4)红绿颜色反应在感受器水平是独立的,在传递神经冲动的过程中是拮抗的。(5)对正常人在有颜色的情况下以识别颜色为主;对于色觉异常者,则以辨别亮度为主。     

先天性色觉异常颜色视觉诱发电位的初步研究

目的　探讨先天性色觉异常的颜色视觉诱发电位特征 ,为先天性色觉异常的临床研究提供新的方法。方法　用计算机软件技术 ,PR 65 0分光测色计严格控制亮度因素和颜色因素 ,设计并制作了单纯亮度对比、亮度对比联合颜色对比、单纯颜色对比三组视觉刺激条件 ,第一组为黑 白棋盘格翻转刺激条件 ,第二组为红 白、绿 白和灰 白格三种刺激条件 ,第三组为红 绿、红 灰、绿 灰格三种刺激条件。分别对 45例正常儿童和 1 8例色觉异常儿童进行多导彩色图形翻转视觉诱发电位 (CP VEP)的研究。结果　第一组单纯亮度对比刺激条件下 ,色觉异常组和正常组比较 ,P1波的潜伏期和振幅均无显著性差异 (P >0 0 5 )。第二组亮度对比联合颜色对比刺激条件下 ,正常组P1波潜伏期比较 ,灰 白格比红 白格延长 1 6ms (P <0 0 5 ) ,色觉异常组P1波潜伏期和振幅无显著性差异 (P >0 0 5 ) ,红 白格刺激条件下 ,异常组的P1波潜伏期比正常组延长 4 3ms,差异有显著性 (P <0 0 5 )。第三组单纯颜色对比刺激条件下 ,正常组P1波潜伏期比较 ,差异有高度显著性 (P <0 0 1 ) ,色觉异常组P1波潜伏期和振幅均无显著性差异 (P >0 0 5 ) ,红 灰格和红 绿格刺激时 ,色觉异常组的P1波潜伏期比正常组分别延长 1 7 8ms和 9 1ms ,差异有高度显     

屈光参差性弱视儿童色觉中枢激活范围的BOLD-fMRI初步研究

目的：利用血氧水平依赖性功能磁共振成像(blood oxygen level dependence-functional magnetic resonance imaging,BOLD-fMRI)及SPM8软件研究分析经过系统治疗后屈光参差性弱视儿童色觉中枢激活区域的恢复情况。

方法：自身前后对照研究。利用3.0T超导磁共振采集13例屈光参差性弱视儿童色觉中枢激活区域的试验数据,采用组块设计方案,以三原色作为刺激源获取色觉皮层激活区功能核磁共振数据,应用基于MATLAB软件下的运行的SPM8对数据进行预处理及分析,对比初诊、治疗1,2,4wk后色觉中枢激活区域的变化。

结果：弱视初诊患儿接受三原色刺激后,BA17,BA18,BA19,BA37均有不同范围的激活(P<0.01)。经过4wk治疗后,弱视患儿接受红色刺激后,视觉皮层激活范围无扩大; 接受绿色刺激后,视觉皮层左侧BA37、左侧BA19、左侧BA20激活范围均有不同程度扩大,平均t值分别为3.5210,3.2716,3.1534(P<0.01); 接受蓝色刺激后,视觉皮层右侧BA19、右侧BA18激活范围有不同程度扩大,平均t值分别为3.7345,3.2701(P<0.01)。

结论：经过4wk的系统治疗后屈光参差性弱视儿童色觉中枢激活范围较初诊时增大但幅度较低,经短期治疗弱视患儿色觉中枢有一定程度的恢复但不明显。     

利用视动性转鼓视力仪对豚鼠色觉和对比度视力的检测

目的 研发一种可以快速定量检测动物的对比敏感度视力、色觉的装置,并用该装置来评价豚鼠的对比敏感度视力和色觉.方法 实验研究.根据豚鼠视细胞的光谱敏感性函数曲线,选取绿、蓝、黄三种不同颜色,制作绿-白、蓝-白和黄-绿三种颜色组合且空间频率均为0.6 c/d的方波条栅视标,每种颜色组合的条栅视标分别又具有高、中、低三种对比度.对于黑白方波条栅,选用3.0 c/d空间频率,制作对比度分别为100%、50%、25%的条栅.将条栅视标贴附在可以转动的圆形鼓内壁,利用豚鼠对运动物体会产生有规律的视动性头部追随运动这一生理现象,在受试豚鼠保持清醒的自然状态下,用视动性转鼓视力仪来初步检测豚鼠的色觉及对比敏感度视力.采用非参数检验中的Kruskal-Wallis检验分析豚鼠在不同对比度下的头部运动追随率.结果 用视动性转鼓视力仪,可以在行为学上验证豚鼠的色觉.豚鼠对空间频率为0.6 c/d的绿、蓝、黄三种颜色组合的方波条栅表现出良好的头部追随运动,在低对比度下,豚鼠的头部运动追随率分别为1.06±0.14（实际对比度为2.41%）、1.12±0.17（实际对比度为1.87%）、1.05±0.15（实际对比度为6.50%）.对于空间频率为3.0 c/d的黑白方波条栅,当对比度降到25%时,豚鼠仍可表现出明确的头部追随运动,其头部运动追随率为0.74±0.08,与高对比度条栅下的追随率经非参数检验分析,差异无统计学意义（x2=2.47,P＞0.05）.结论 转鼓视力仪可以检测豚鼠的颜色视觉并定量确定其颜色对比敏感度视力.该实验装置及实验流程操作简单,可以用于豚鼠色觉和视力的检查.     

Influence of cone pigment coexpression on spectral sensitivity and color vision in the mouse

The mouse retina contains both middle-wavelength-sensitive (M) and ultraviolet-sensitive (UV) photopigments that are coexpressed in cones. To examine some potential visual consequences of cone pigment coexpression, spectral sensitivity functions were measured in mice (Mus musculus) using both the flicker electroretinogram (ERG) and behavioral discrimination tests. Discrimination tests were also employed to search for the presence of color vision in the mouse. Spectral sensitivity functions for the mouse obtained from ERG measurements and from psychophysical tests each reveal contributions from two classes of cone having peak sensitivities (lambda(max)) of approximately 360 and 509-512 nm. The relative contributions of the two pigment types to spectral sensitivity differ significantly in the two types of measurements with a relationship reversed from that often seen in mammals. Mice were capable of discriminating between some pairs of spectral stimuli under test conditions where luminance-related cues were irrelevant. Since mice can make dichromatic color discriminations, their visual systems must be able to exploit differences in the spectral absorption properties among the cones. Complete selective segregation of opsins into individual photoreceptors is apparently not a prerequisite for color vision.     

Psychophysical studies of pigeon color vision—II. The spectral photochromatic interval function

A two-choice operant discrimination procedure was used to determine the spectral photochromatic interval function for the red field of the pigeon visual system under light adaptation. The interval is largest at about 600 nm. and falls to very low values at the spectral extremes. The data are consistent with a proposed model of the visual system which assumes that achromatic spectral sensitivity is determined by an additive combination of responses from cones containing a 562-nm pigment (iodopsin) and from cones containing a postulated pigment with a peak absorption at 415 nm: and that chromatic sensitivity arises from opponent interactions between responses from these same cones.     

Visual impairment and the useful field of vision

The aim of this study was to measure the useful field of vision (UFoV) in people with visual impairment and to compare results with clinical measures of vision. UFoV, visual acuity, contrast sensitivity and visual fields were measured in 36 participants with low vision and 22 age-matched controls in two age groups. For both the low vision and control groups the presence of distractors (cluttered field) increased the error rates on our UFoV measure but there was no significant effect of the presence of a central task (divided attention). Participants with low vision made more errors on UFoV than did controls, but this difference disappeared once their visual field defects were accounted for. By multiple regression analysis, age, visual fields and contrast sensitivity were shown to predict the different UFoV scores. As for observers with normal vision, standard clinical visual field tests may not fully describe the difficulties that may be encountered by people with visual impairment undertaking tasks in the cluttered environments and multiple demands of everyday life.     

Behavioral spectral sensitivity of the zebrafish (Danio rerio)

While the zebrafish (Danio rerio) continues to become an important animal model for the investigation of the genetic and physiological bases of visual processing of the vertebrate retina, its visual behavior, particularly regarding color processing, has received little attention. The purpose of this study was to obtain behavioral spectral sensitivity functions from adult zebrafish using an appetitive instrumental conditioning procedure. A three-chamber maze was implemented to train light-adapted adult zebrafish to swim into the chamber that contained a suprathreshold monochromatic stimulus for a food reward. Visual threshold was determined by varying the stimulus irradiance using a 'two-down one-up' staircase procedure. Threshold values were obtained for wavelengths from 340 to 640 nm. Spectral sensitivity functions obtained show contributions from two nonopponent cone mechanisms (UV and S) and two opponent mechanisms (M-S and L-M). These cone mechanisms are qualitatively similar to those obtained via physiological measures from the On-responses of the zebrafish retina and optic tectum. However, the functions are not quantitatively similar suggesting that further visual processing takes place beyond the processing of the retinal circuitry and processing of the initial stages of the optic tectum. These results demonstrate that the zebrafish is an excellent model to examine and compare the relationship between physiological and behavioral color processing.     

The genetics of normal and defective color vision

The contributions of genetics research to the science of normal and defective color vision over the previous few decades are reviewed emphasizing the developments in the 25 years since the last anniversary issue of Vision Research. Understanding of the biology underlying color vision has been vaulted forward through the application of the tools of molecular genetics. For all their complexity, the biological processes responsible for color vision are more accessible than for many other neural systems. This is partly because of the wealth of genetic variations that affect color perception, both within and across species, and because components of the color vision system lend themselves to genetic manipulation. Mutations and rearrangements in the genes encoding the long, middle, and short wavelength sensitive cone pigments are responsible for color vision deficiencies and mutations have been identified that affect the number of cone types, the absorption spectra of the pigments, the functionality and viability of the cones, and the topography of the cone mosaic. The addition of an opsin gene, as occurred in the evolution of primate color vision, and has been done in experimental animals can produce expanded color vision capacities and this has provided insight into the underlying neural circuitry.     

A review of the evolution of animal colour vision and visual communication signals

The visual displays of animals and plants are often colourful, and colour vision allows animals to respond to these signals as they forage for food, choose mates and so-forth. This article discusses the evolutionary relationship between photoreceptor spectral sensitivities of four groups of land animals—birds, butterflies, primates and hymenopteran insects (bees and wasps)—, the colour signals that are relevant to them, and how understanding is informed by models of spectral coding and colour vision. Although the spectral sensitivities of photoreceptors are known to vary adaptively under natural selection there is little evidence that those of hymenopterans, birds and primates are specifically adapted to the reflectance spectra of food plants or animal visual signals. On the other hand, the colours of fruit, flowers and feathers may have evolved to be more discriminable for the colour vision of their natural receivers than for other groups of animals. Butterflies are unusual in that they have enjoyed a major radiation in receptor numbers and spectral sensitivities. The reasons for the radiation and diversity of butterfly colour vision remain unknown, but may include their need to find food plants and to select mates.