PS：时间仓促，后期再翻译讲解
一、专业词汇解释
Pathology：[pəˈθɑlədʒi] the scientific study of diseases 病理学
ora serrata：锯状缘
ciliary body ：睫状体;
ciliary：['sɪlɪərɪ] 睫毛的，纤毛的，毛状的;
posterior chamber：后房;
chamber：[ˈtʃembɚ] a space in the body, in a plant or in a machine, which is separated from the rest （人体、植物或机器内的）腔，室
posterior：[pɑˈstɪriə] (technical 术语) located behind sth or at the back of sth 在后面的；在后部的
anterior：[ænˈtɪriə®] (technical 术语) (of a part of the body 身体部位) at or near the front 前部的；前面的
anterior chamber：前房;
cornea：[ˈkɔrniə] (anatomy 解) the transparent layer which covers and protects the outer part of the eye 角膜
pupil：[ˈpjupəl] the small round black area at the centre of the eye 瞳孔；眸子；瞳人
constrict：[kənˈstrɪkt] to become tighter or narrower; to make sth tighter or narrower （使）紧缩，缩窄
dilate：to become or to make sth larger, wider or more open 扩大；（使）膨胀，扩张
iris：[ˈaɪrɪs] the round coloured part that surrounds the pupil of your eye 虹膜
zonules：小带
sclera：['sklɪrə] 巩膜
optometry: the job of measuring how well people can see and checking their eyes for disease 验光；视力测定
retina：[ˈretənə] a layer of tissue at the back of the eye that is sensitive to light and sends signals to the brain about what is seen 视网膜
anatomy：[əˈnætəmi] the structure of an animal or a plant （动植物的）结构，解剖
fovea centralis：[sɛnˈtrelɪs] （视网膜的）中央凹;
optic：(technical 术语) connected with the eye or the sense of sight 眼的；视觉的
optic nerve：视神经;
vitreous：[ˈvɪtriəs] (technical 术语) hard, shiny and transparent like glass 玻璃质的；透明的
inferior rectus：下直肌the ocular muscle whose contraction turns the eyeball down and medially
ocular：(technical 术语) connected with the eyes 眼的；眼睛的
mucus：粘液 a thick liquid that is produced in parts of the body, such as the nose, by a mucous membrane 黏液；鼻涕
hydrate：[ˈhaɪˌdret] (technical 术语) to make sth absorb water 使吸入水分；使水合；使成水合物
dome：a round roof with a circular base 穹顶；圆屋顶
aqueous：[ˈeɪkwiəs] (technical 术语) containing water; like water 水的；含水的；水状的
humor：[ˈhjumɚ] the liquid parts of the body
pigment：a coloured powder that is mixed with a liquid to produce paint, etc. 颜料
lens：[lɛnz] (anatomy 解) the transparent part of the eye, behind the pupil , that focuses light so that you can see clearly （眼球的）晶状体
crystalline：[ˈkrɪstəlaɪn] (technical 术语) made of or similar to crystals 结晶的；水晶制的；晶状的
choroid：['kɔɔɪd] 脉络膜
supensory ligament： 悬吊的韧带
bent：not straight 弯曲的
converge：(of people or vehicles 人或车辆) to move towards a place from different directions and meet 汇集；聚集；集中
gel：[dʒɛl] a thick substance like jelly, especially one used in products for the hair or skin 凝胶，冻胶，胶滞体（尤指用于头发或护肤的产品）
macula：['mækjʊlə] 斑点; a yellowish central area of the retina that is rich in cones and that mediates clear detailed vision
yellowish：fairly yellow in colour 微黄色的；发黄的
cones：圆锥细胞
mediate：to try to end a disagreement between two or more people or groups by talking to them and trying to find things that everyone can agree on 调停；调解；斡旋
photon：[ˈfoʊtɑn] (physics 物) a unit of electromagnetic energy 光子；光量子
occipital：[ɒk’sɪpətəl] 枕部的，枕骨的;
cortex：[ˈkɔrteks] the outer layer of an organ in the body, especially the brain 皮层；皮质；（尤指）大脑皮层
myopia：[maɪˈoʊpiə] (technical 术语) the inability to see things clearly when they are far away 近视
nearsightedness：近视; 目光短浅; 短视;
hyperopia：[ˌhaɪpə’roʊpɪr] 远视; abnormal condition in which vision for distant objects is better than for near objects
astigmatism：[əˈstɪɡməˌtɪzəm] 散光 a fault in the shape of a person’s eye that prevents them from seeing clearly 散光
refractive：[rɪˈfræktɪv] (physics 物) causing, caused by or relating to refraction （由）折射引起的；折射的
spherical：[ˈsferɪkl] shaped like a sphere 球形的；球状的
cylindrical：[səˈlɪndrɪkəl] shaped like a cylinder 圆柱形的；圆筒状的
toric：['tɒrɪk] 环形圆纹曲面的，环面的;
smear：胡乱涂抹; 弄脏; 诽谤; 变得模糊不清; to rub writing, a drawing, etc. so that it is no longer clear; to become not clear in this way 把（字迹、图画等）蹭得模糊不清；变得模糊不清
presbyopia：[ˌprezbiˈoʊpiə] (medical 医) the condition, that is usually found in older people, when sb is not able to see clearly objects that are close 老视；老花眼；老光
cavity：[ˈkævɪti] a hole or empty space inside sth solid 洞；孔；窟窿；腔
extracellular：[ˌekstrə’seljʊlə] （位于或发生于）细胞外的;
二、人眼的解剖、生理及病理
The human eye is the organ which gives us the sense of sight, allowing us to observe and learn more about the surrounding world than we do with any of the other four senses. We use our eyes in almost every activity we perform, whether reading, working, watching television, writing a letter, driving a car, and in countless other ways. Most people probably would agree that sight is the sense they value more than all the rest.
The eye allows us to see and interpret the shapes, colors, and dimensions of objects in the world by processing the light they reflect or emit. The eye is able to detect bright light or dim light, but it cannot sense objects when light is absent.
process of vision
Light waves from an object (such as a tree) enter the eye first through the cornea, which is the clear dome at the front of the eye. It is like a window that allows light to enter the eye. The light then progresses through the pupil, the circular opening in the center of the colored iris.
Fluctuations in the intensity of incoming light change the size of the eye’s pupil. As the light entering the eye becomes brighter, the pupil will constrict (get smaller), due to the pupillary light response. As the entering light becomes dimmer, the pupil will dilate (get larger).
Initially, the light waves are bent or converged first by the cornea, and then further by the crystalline lens (located immediately behind the iris and the pupil), to a nodal point (N) located immediately behind the back surface of the lens. At that point, the image becomes reversed (turned backwards) and inverted (turned upside-down). The light impulses of the image are reoriented before reaching the visual center at the back of the brain.
The light continues through the vitreous humor, the clear gel that makes up about 80% of the eye’s volume, and then, ideally, back to a clear focus on the retina, behind the vitreous. The small central area of the retina is the macula, which provides the best vision of any location in the retina. If the eye is considered to be a type of camera (albeit, an extremely complex one), the retina is equivalent to the film inside of the camera, registering the tiny photons of light interacting with it.
Within the layers of the retina, light impulses are changed into electrical signals. Then they are sent through the optic nerve, along the visual pathway, to the occipital cortex at the posterior (back) of the brain. Here, the electrical signals are interpreted or “seen” by the brain as a visual image.
Actually, then, we do not “see” with our eyes but, rather, with our brains. Our eyes merely are the beginning of the visual process. Watch an 11½-minute film, created in 1941, about the anatomy and physiology of the eye: How the Eye Functions.
myopia, hyperopia, astigmatism
If the incoming light from a far away object focuses before it gets to the back of the eye, that eye’s refractive error is called “myopia” (nearsightedness). If incoming light from something far away has not focused by the time it reaches the back of the eye, that eye’s refractive error is “hyperopia” (farsightedness).
In the case of “astigmatism,” one or more surfaces of the cornea or lens (the eye structures which focus incoming light) are not spherical (shaped like the side of a basketball) but, instead, are cylindrical or toric (shaped a bit like the side of a football). As a result, there is no distinct point of focus inside the eye but, rather, a smeared or spread-out focus. Astigmatism is the most common refractive error.
presbyopia (“after 40” vision)
After age 40, and most noticeably after age 45, the human eye is affected by presbyopia. This natural condition results in greater difficulty maintaining a clear focus at a near distance with an eye which sees clearly far away.
Presbyopia is caused by a lessening of flexibility of the crystalline lens, as well as to a weakening of the ciliary muscles which control lens focusing. Both are attributable to the aging process.
An eye can see clearly at a far distance naturally, or it can be made to see clearly artificially, such as with the aid of eyeglasses or contact lenses, or else following a photorefractive procedure such as LASIK (laser-assisted in situ keratomileusis). Nevertheless, presbyopia eventually will affect the near focusing of every human eye.
eye growth
The average newborn’s eyeball is about 18 millimeters in diameter, from front to back (axial length). In an infant, the eye grows slightly to a length of approximately 19½ millimeters.
The eye continues to grow, gradually, to a length of about 24-25 millimeters, or about 1 inch, in adulthood. A ping-pong ball is about 1½ inch in diameter, which makes the average adult eyeball about 2/3 the size of a ping-pong ball.
The eyeball is set in a protective cone-shaped cavity in the skull called the “orbit” or “socket.” This bony orbit also enlarges as the eye grows.
extraocular muscles
The orbit is surrounded by layers of soft, fatty tissue. These layers protect the eye and enable it to turn easily.
Traversing the fatty tissue are three pairs of extraocular muscles, which regulate the motion of each eye: the medial & lateral rectus muscles, the superior & inferior rectus muscles, and the superior & inferior oblique muscles.
eye structures
Several structures compose the human eye. Among the most important anatomical components are the conjunctiva, cornea, crystalline lens, extraocular muscles, iris, macula, optic nerve, retina, and vitreous humor.
You can click on the names of each of these 9 ocular structures on the left (either in the upper picture or in the lower frame of links) to learn more about them. Then take three short quizzes, if you wish.
Anatomy、Physiology & Pathology of the Human Eye
三、Layers of the Human Eye
Almost every one of us has seen how a human eye looks like from just looking in your own mirror, but what if you could see though the entire eye all the way back to the retina or the optic nerve. Wouldn’t that be an exciting tour to take?!
Many believe that the 1st layer of the human eye is the cornea, but it is actually the tear film. The tear film is made up of three layers: oil, water and mucus. The oil locks in the water, so it won’t evaporate easily and the mucus serves as a foundation for the water and oil to hold on the cornea. The tear layer keeps the eye hydrated, nourished and free from harmful bacteria.
The 2nd layer of the human eye is the cornea, a transparent dome shaped tissue that consists of 5 layers starting from the top to bottom: the epithelium, Bowman’s layer, the stroma, Descemet’s membrane and endothelium. The main purpose of the cornea is to help focus light that is entering the eye.Behind the cornea is the anterior chamber, an area where aqueous humor fluid flows in and out to rehydrate and nourish the cornea.
The 3rd layer of the eye is the iris, which looks like a pigmented disk-like tissue that can widen and close to regulate the amount of light that can enter the eye. The middle opening of the iris is called the pupil. The iris has 3 layers: the endothelium, the stroma and the epithelium.
After the iris is a transparent crystalline lens, which is composed of 4 layers from starting from the surface to center: capsule, subcapsular epithelium, cortex, and nucleus. The lens acts by focusing light rays onto the retina. However, before the light rays hit the retina, it will first go through the posterior chamber and the vitreous humor, which makes up 80% of the entire eye. The vitreous humor is a clear, jelly-like substance that helps retain the shape of eye.
The 5th and innermost layer of the eye is the retina. It has a total of 10 layers that have light sensitive cells which include rods and cones. These light sensitive cells create signals that travel down the optic nerve and to the back of the brain for further understanding of what we are seeing. The 6th layer of the eye is the choroid, which is filled with blood vessels that help supply blood to the retina. Finally the last layer of the eye is the sclera, a white tissue that covers the whole eye (until the cornea) with muscles attached to allow movement of the eye in the eye socket.
Although, there many layers within the eye, that there are also many other processes such as the ciliary body which produces the aqueous humor in the anterior chamber and supensory ligaments that keep the lens in place.