Neural basis of orientation perception in primate vision

Orientational differences in human visual acuity can be related parametrically to the distribution of optimal orientations for the receptive fields of neurons in the striate cortex of the rhesus monkey. Both behavioral measures of acuity and the distribution of receptive fields exhibit maximums for stimuli horizontal or vertical relative to the retina; the effect diminishes with distance from the fovea. The anisotropy in the neuronal population and in visual acuity appear to be determined by postnatal visual experience.     

Conditioned vocalizations as a technique for determining visual acuity thresholds in sea lions

Aerial visual acuity and underwater visual acuity were measured in two sea lions (Zalophus californianus) by training them to emit click bursts if they saw a striped target or to remain silent if they saw a gray target. The closest grating spacings that could be resolved both in air and under water subtended a visual angle of 5.5 minutes of arc at a distance of 5.5 meters.     

Visual acuity in a stumptail macaque

Visual acuity in a normal stumptail macaque is 1.4 minutes of arc-similar to man's. Destruction of the fovea by photocoagulation decreased acuity to 9 minutes of arc. These facts suggest that the fovea in the macaque has the same physiological role in visual acuity as in man.     

Accurate visual measurement of three-dimensional moving patterns

Human observers discriminated relative three-dimensional distances in simple patterns of motion parallax with an acuity similar to vernier acuity under comparable conditions. Accurate visual measures of three-dimensional distance can be derived from the structural invariance of patterns undergoing perspective transformations.     

Comparison of the effects of striate cortex and retinal lesions on visual acuity in the monkey

Acuity falls sharply and predictably in man as fixation is shifted away from the test stimulus. If the same "eccentricity" function applies to the monkey, then it can be shown that striate cortex lesions produce a smaller acuity impairment than is predicted by electrophysiological maps of the projection of retina onto the cortex. It is seen in this study that retinal lesions of the fovea and adjacent parafovea produce a more severe drop in acuity than corresponding cortical lesions, and therefore the surprisingly slight effects of the latter cannot be explained in terms of a relatively higher parafoveal acuity in the monkey. The discrepancy between retinal and cortical effects is unlikely to be due to the development of "supersensitivity" at the edge of the cortical lesions. An explanation is proposed in terms of lateral spread of information at retinal and/or geniculate stages of the visual system.     

养阴清热、活血利水方联合西药治疗糖尿病视网膜病变激光术后的疗效观察

目的 观察养阴清热、活血利水中药复方联合抗血管内皮生长因子（vascular endothelial growth factor,VEGF）药物治疗糖尿病视网膜病变激光术后的临床疗效。方法 将视网膜激光光凝治疗的糖尿病视网膜病变患者60例,根据不同的治疗方法,分为抗VEGF药物治疗组（对照组）和养阴清热活血利水中药复方+抗VEGF药物治疗组（观察组）,观察两组患者疗程结束后4周、半年的最佳矫正视力、黄斑中心凹厚度变化、中医症候、注射抗VEGF次数及总体疗效的情况,比较两种治疗方法的综合疗效。结果 疗程结束4周后,两组的视力、黄斑中心厚度、中医症候、总体疗效差异无统计学意义（P>0.05）;疗程结束半年后,观察组的视力、黄斑中心厚度、中医症候、总体疗效优于对照组,差异有统计学意义（P<0.05）;观察组注射抗VEGF次数明显少于对照组（P<0.05）。结论 养阴清热活血利水中药复方联合抗VEGF药物治疗糖尿病视网膜病变激光术后患者的远期疗效优于单纯抗VEGF药物治疗。     

Testing the vision of cataract patients by means of laser-generated interference fringes

In a new technique for measuring the visual acuity of cataract patients the light from a laser is used to form interference patterns of variable fineness on the patient's retina. The fineness of the interference pattern that the patient can detect gives an indication of the potential for improved vision. Comparison of this estimate of the potential with the patient's vision after cataract extraction shows that this test can indicate the condition of the fovea behind a cataract.     

活血通络汤联合西药治疗糖尿病视网膜神经病变的临床观察

目的 观察活血通络汤联合羟苯磺酸钙治疗糖尿病视网膜神经病变（diabetic retinopathy,DR）的临床疗效及对视力的影响。方法 将82例DR患者按照随机数字表法分为观察组和对照组,每组41例。对照组采用常规治疗加以羟苯磺酸钙分散片治疗,观察组在对照组的基础上联合活血通络汤治疗。1个月为1个疗程,连续治疗3个疗程。观察比较两组患者临床疗效、治疗前后视力变化、视野缺损积分、视敏度情况及一氧化氮、丙二醛、超氧化物歧化酶水平。结果 观察组临床总有效率92.68%,显著高于对照组73.17%（P<0.05）。治疗后观察组的视力、30°视敏度、30°~60°视敏度显著高于对照组（P<0.05）,视野缺损积分显著低于对照组（P<0.05）;观察组一氧化氮、丙二醛水平显著低于对照组（P<0.05）,超氧化物歧化酶水平显著高于对照组（P<0.05）。所有患者在治疗期间未出现不良反应。结论 活血通络汤联合羟苯磺酸钙治疗DR,能有效改善患者临床症状,临床疗效良好,安全性较高。     

Age differences in infants' attention to patterns of different complexities

Infants 3 weeks, 8 weeks, and 14 weeks old were presented with checkerboard patterns which differed in the number of squares they contained. The older the infants, the more complex was the checkerboard that they looked at longest. This result does not appear to depend on changes in visual acuity or accommodation related to age.     

虚拟火场环境因子对森林消防车驾驶员间接视野的影响

从森林消防车间接视野的传统检测缺陷入手,建立森林消防车间接视野虚拟测试系统,得出在虚拟火场环境 下森林消防车驾驶员间接视野衰减的测试数值。结果表明:驾驶员的间接视野衰减会导致森林消防车出勤事故; 在驾驶员的间接视野衰减中,C 柱盲区略有增大;前进时的驾驶员间接视野衰减幅度小于后退时;定点光源频闪下 的间接视野衰减小,移动光源频闪下的间接视野衰减大;同等光线环境下,配合烟雾和噪声时的间接视野衰减最明 显;驾驶员在明视觉状态下的间接视野衰减不明显,暗视觉状态下的间接视野衰减明显。      

黔西南南龙布依古寨4种染食植物研究进展

黔西南布依族苗族自治州南龙布依古寨有枫香树叶染黑色、紫草染紫色、密蒙花染黄色、苏木染红色及糯米本色白色组成的五色米,有养脾胃、养肝明目、消炎下肿等功效。对五色米中枫香叶、密蒙花、紫草及苏木4种染色植物的化学成分、功能及应用研究进行归纳,为民间药用植物的应用开发、促进民族地区植物资源的开发利用和民族特色文化保护提供参考。     

Differential acuity of the two eyes and the problem of ocular dominances

While it has long been thought that no relationship exists between the eye of greater visual acuity and the eye favored in sighting, the data collected suggest the need for a re-examination of this issue. Sighting-dominance and acuity-dominance were associated. In addition, most individuals tested showed acuity-dominance of the left eye.     

公路景观视觉影响评价研究

针对公路视觉影响评价的特点分析了公路视觉影响评价的主客体,其中主体是指"人"这一观察者,客体是指景观视觉资源、景观视觉特征和景观视觉质量。基于这两者笔者提出高速公路视觉影像评价的内容、评估模型,并进一步介绍了公路视觉相融性评价和预测视觉质量变化的方法,最后从避免、减少、修复、补偿4个角度提出公路视觉影响的缓和措施,旨在将公路建设中对景观视觉环境的影响减少到最低程度。     

Photonic crystal light collectors in fish retina improve vision in turbid water

Despite their diversity, vertebrate retinae are specialized to maximize either photon catch or visual acuity. Here, we describe a functional type that is optimized for neither purpose. In the retina of the elephantnose fish (Gnathonemus petersii), cone photoreceptors are grouped together within reflecting, photonic crystal-lined cups acting as macroreceptors, but rod photoreceptors are positioned behind these reflectors. This unusual arrangement matches rod and cone sensitivity for detecting color-mixed stimuli, whereas the photoreceptor grouping renders the fish insensitive to spatial noise; together, this enables more reliable flight reactions in the fish's dim and turbid habitat as compared with fish lacking this retinal specialization.     

Visual acuity and contrast sensitivity in patients with cerebral lesions

Spatial contrast sensitivity as a function of spatial frequency was measured in patients with cerebral lesions. In most of these patients visual acuity, as measured by the Snellen chart, was 20/30 or better, yet marked departures from normal contrast sensitivity were found. The greatest loss in contrast sensitivity occurred at high frequencies, but in one patient the loss was greatest in the midfrequency range. This finding lends support to the channel hypothesis of spatial contrast discrimination.     

Development of contrast sensitivity in infant Macaca nemestrina monkeys

During an infant monkey's first 28 postnatal weeks, the visual contrast sensitivity function develops its characteristic adult form. Contrast sensitivity is depressed relative to that of the adult for all spatial frequencies during the early postnatal weeks. Absolute sensitivity to frequencies below 5 cycles per degree approaches adult levels by 20 weeks after birth, whereas sensitivity to fine spatial detail continues to develop through 28 weeks. The results imply that the development of primate spatial vision is more complex than just an improvement in the ability to resolve acuity gratings.     

Visual experience without lines: effect on developing cortical neurons

Kittens were reared in a planetarium-like visual environment that lacked straight line contours. Cortical neurons were subsequently highly sensitive to spots of light but not to straight lines, in marked contrast to those from a normal cat. If linear contour processing is an innate function it appears to be subject to substantial modification by early visual experience.     

中国胆毒鱼类的研究

在我国民间想念吞服鱼胆可治目疾，然而因吞服鱼胆面 引起的中毒，危害身体健康事件时有发生，自1964-1999年的35年中，据不完全统计吞服有毒鱼胆而中毒的人类达451人，其中死亡达83人，死亡率为18.04%，本文主要叙述鱼胆中毒的概况，胆汁有毒成分（鲤醇），动物实验，中毒症状及治疗，经动物实验及多年的调研共发现12种淡水鱼类的胆汁有毒，它们均是鲤科鱼类，从理论上阐明吞服任何鲤科鱼类的鱼胆均是危险的。     

中国胆毒鱼类的研究

在我国民间想念吞服鱼胆可治目疾，然而因吞服鱼胆面 引起的中毒，危害身体健康事件时有发生，自1964-1999年的35年中，据不完全统计吞服有毒鱼胆而中毒的人类达451人，其中死亡达83人，死亡率为18.04%，本文主要叙述鱼胆中毒的概况，胆汁有毒成分（鲤醇），动物实验，中毒症状及治疗，经动物实验及多年的调研共发现12种淡水鱼类的胆汁有毒，它们均是鲤科鱼类，从理论上阐明吞服任何鲤科鱼类的鱼胆均是危险的。