一种简单实用的眼睛屈光不正的模拟与矫正的实验方法

利用物距、像距法测量薄透镜的焦度是几何光学中最常用的方法.本实验利用透镜A来模拟了眼睛的折光系统,像屏模拟了视网模,透镜B、C分别模拟了矫正眼睛屈光不正的近视镜和远视镜,屈光不正的原因很多[8,9],本文仅以眼球前后距离的变化(视网膜的移动[9]靠像屏的移动来实现)来模拟了眼睛的屈光不正及矫正的方法,并比较准确地测定了薄透镜的焦距(光焦度).本文是在"非正常眼的模拟与矫正的实验方法研究"的基础上又进行了改进.     

近视眼模拟与矫正光学系统成像分析

介绍薄透镜成像原理和眼屈光系统。分析近视眼的模拟与矫正。     

薄透镜成清晰象方法的定量描述

本文主要针对在测定薄凸透镜的焦距实验中,当物在光具座上的位置确定后,固定光屏移动透镜与固定透镜移动光屏两种情况下,光屏上所成象的清晰程度出现差异的现象进行了探讨。并分析出其原因是由于在移动透镜及移动光屏的两种成象过程中,所引起的象与光屏之间的相对速度大小不同所致,且对其做出了相应的定量描述和实验验证。     

易制作、具有良好透氧性能的接触透镜聚合物

澳大利亚研究人员,研制了一种用于制作软接触透镜的材料相比,这种材料与目前透境使用的材料相比,透氧性能好,且易于制作。据“澳洲周末”报道,这种透镜与目前软接触镜相比,透氧率多8倍,而且制造费用减少30%。悉尼的透镜制作公司是     

教学扎记:(五)单透镜的角放大和线放大

透镜给出的象长对物长的比值叫线放大。用透镜时物或象的视角对不用透镜时物在明视距离时的视角的比值叫角放大。应说明。透镜并没有放大物体的视角,其作用是使物体能够放得到近一些并在网膜成清晰象。我们应从这一角度理解角放大。显微镜的物镜作用是线放大,目镜作用是角放大。显微镜的总放大是二者的乘积,实际是角放大。关于放大镜,一般将线放大和角放大分开讨论,因物在透镜焦点时,线放大变为无穷大     

股薄肌的局部解剖学研究与临床

本文对25具50侧下肢的股薄肌进行了解剖观察。虽然股薄肌的动脉来源有多处,但主要血管是来自股深动脉的股薄肌支,该血管与股薄肌的支配神经构成血管神经束,血管神经束位于耻骨结节下90～160mm范围内,52％的位于130～140mm之间。所以,临床移植股薄肌对其游离在耻骨结节下方160mm以下进行,即不会损伤股薄肌的血管神经束。     

股薄肌的应用解剖学研究

<正> Harii等1976年游离股薄肌到患者的面部治疗面瘫获得成功以来,股薄肌瓣已广泛应用于临床。有关股薄肌的血管神经供应的研究,二军大解剖室、熊树明等、甄德儒等有过报导。为了进一步累积显微外科应用解剖学资料,本文对股薄肌进行了观察。     

股薄肌及其血管的观察

观察了 68侧股薄肌的形态及血管分布。股薄肌的平均长度为 4 1.4 2± 2 .88cm,其肌腱长为 11.71± 2 .72 cm。股薄肌的动脉平均为 3.63支 ,其入肌处以距耻骨联合下缘的 6～ 10 cm者多见     

带血管蒂股薄肌瓣的应用解剖

随着显微外科的不断发展,用带血管蒂的肌瓣如带血管蒂股薄肌瓣修复软组织损伤,在临床上日渐广泛。为积累有关股薄肌的解剖学资料,并为临床提供解剖学依据,本文对股薄肌的血液供应,血管蒂长度、外径、走行和神经支配进行了应用解剖学观测。     

带血管蒂股薄肌瓣转位修补复发性腹股沟疝的应用解剖

目的：为带血管蒂股薄肌瓣转位修补复发性腹肚沟疝提供解剖学基础。方法：在５０侧成人男性下肢标本上，密切结合带血管蒂股薄肌瓣转位修复复发性腹股沟疝的术式，对股薄肌的血管、神经分布等进行了解剖学观测。结果：以股薄肌中上段动脉为蒂肌瓣转位长度可达２１．３±２．６ｃｍ；而肌瓣转位至腹股沟管度环所需长度为１８．０±２．２ｃｍ。股薄肌有多血供来源，在肌内有丰富的血管吻合，以该肌主要供血动脉为蒂，可保证转位肌瓣的血供。结论：以中上段血管为蒂股薄肌瓣转位修补复发性腹肚沟疝术式具有可行性。     

The Experimental Study on Implantation of Intraocular Lens in Different Animals

To prevent the complications in cataract surgeries, the eyes of rabbits and monkeys were implanted with intraocular lens for 360 days. Methods: The eyes of the rabbits were performed with phacoemulsification and soft intraocular lens implantation. The eyes of the monkeys were performed with extracapsular cataract extraction and hard intraocular lens implantation. Results: The postoperative reactions included corneal edema, anterior chamber exudation, posterior capsule opacification and so on. The complications in the eyes of the rabbits were more than that in the eyes of the monkeys. Conclusion: The different postoperative reactions happened in different animals. In clinical the choice of the operative method and intraocular lens depended on the case in order to acquire the best sight.     

Forces developed beneath hydrogel contact lenses due to squeeze pressure

The hydrodynamic squeeze pressure in the fluid thin film beneath hydrogel contact lenses fitted onto an axisymmetric model eye were measured. These pressures were due to the contact lens relaxing after deformation by an applied force of similar magnitude to the human eyelid force. The distribution of pressure for contact lenses typically fitted to human eyes was negative with respect to atmospheric pressure at the corneal apex and became less negative at the corneo-scleral limbus. The force that the contact lens applied to the cornea was determined by integrating the pressure distribution from the corneal apex to the limbus. This force varied from 6.0 X 10(-4) N to -7.8 X 10(-1) N depending on the thickness, elastic modulus and bearing relationship of the contact lens. An expression was derived to determine the pressure developed beneath the annulus of the hydrogel contact lens overlapping the cornea, in terms of the measured force over the cornea beneath the contact lens and the chord diameters of the contact lens and cornea. It was found that the deformation of hydrogel contact lenses on the model eye did not follow a linear elastic shell theory.     

疏水性丙烯酸酯折叠式人工晶体的生物安全性

背景：在临床试验前,需对疏水性丙烯酸酯人工晶体以新西兰白兔作为植入对象进行生物学评价。目的：观察新型疏水性丙烯酸酯折叠式人工晶体的生物安全性。方法：取新西兰家兔12只,右侧眼做实验眼,植入沈阳百奥医疗器械有限公司研制疏水性丙烯酸酯折叠式人工晶体,左侧眼做对照眼,植入美国爱尔康公司的Acrysof IQ SN60WF人工晶体。结果与结论：与对照眼相比,兔实验眼植入后各时间点角膜、前房、植入物位置、眼后节变化差异无显著性意义;且角膜和晶体囊袋无炎症反应,组织增生差异无显著性意义;人工晶体表面无巨噬细胞等炎症细胞,晶体表面、襻根部可见纤维组织。说明此款新材料与临床中已经广泛应用的产品无显著差别,即具有生物安全性。中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

无晶体后囊支撑的后房型人工晶体植入术

目的 探讨无晶体后囊支撑的后房型人工晶体植入术的疗效。方法 对10例单眼无晶体眼患者施行后房型人工晶体植入术。结果 10例患者均成功植入,并获得良好视力。结论 无晶体后囊支撑的后房型人工晶体植入术是一种安全有效的术式。     

Ultrastructural and histochemical observations on the pigmented eyes of the oncomiracidium of Entobdella soleae,a monogenean skin parasite of the common sole,Solea solea

Summary The pigmented eyes of the oncomiracidium of the monogenean skin parasite Entobdella soleae are rhabdomeric in nature, the smaller anterior eyes each containing a single rhabdomere and the larger posterior eyes each containing two rhabdomeres. Each eye has a lens and a single cup-shaped pigment cell. There are differences in the arrangement of the microvilli in the rhabdomeres of the anterior and posterior eyes. Microvilli from each side of the anterior retinular cell are convergent. In each rhabdomere of the posterior eyes most of the microvilli lie parallel to each other but their direction is perpendicular to that of the microvilli of the adjacent posterior rhabdomere. The retinular cell leaves the eye between the pigment cell and the lens, and the retinular cell nucleus lies outside the eye. The darkbrown pigment in the pigment cell was identified as melanin. The lens contains carbohydrate and possibly protein but tests for fat were negative.Key to Lettering of Figs. 1–7 ae anterior eye - ar retinular cell of anterior eye - d desmosome-like thickenings - e eye - ex retinular cell exit from posterior eye - f possible muscle fibre - h haptor - l lens - m mitochondrion - np nucleus of pigment cell - nr nucleus of the retinular cell - pc pigment cell - pe posterior eye - pr retinular cell of posterior eye - rh rhabdomere     

Evidence for the mitochondrial origin of the eye lenses in embryos of Entobdella soleae (Plathelminthes, Monogenea)

The lens associated with each of the four pigmented eyes of the oncomiracidium of Entobdella soleae (Plathelminthes, Monogenea, Capsalidae) develops in a special region of the pigment cup cell of the eye. It is confirmed that the inner of the two membranes enclosing each lens bears short, inwardly projecting, membranous profiles identical to mitochondrial cristae. Studies of embryos incubated for 19 days at 12 degrees C (hatching begins at 28 days at this temperature) revealed that the matrix of the developing lens of each anterior eye contains many mitochondrial membrane compartments, some having the configuration of separate, small mitochondria. The implication is that the lens is derived from many fused mitochondria, rather than from a single large one. The anterior eyes of 19-day-old embryos are less well developed than the posterior eyes. Pigment granules in the anterior eyes appear to be at the premelanosome stage and contain dispersed dense particles lacking an obvious orderly arrangement. The posterior eyes mostly contain mature melanosomes. Membranous compartments in the matrix of the posterior eye lenses are rare. Apart from longer peripheral cristae, lenses of 22-day-old embryos are identical with those of oncomiracidia. The evolution of mitochondrial lenses in Plathelminthes is considered.