《灵枢》大惑论曰∶五脏六腑之精气，皆上注于目而为之精。精之窠为眼，（窠者，
窝也。聚精成窝，搏结之义。）骨之精为瞳子，筋之精为黑眼，血之精为络，（大小 赤络。）其窠气
之精为白眼，肌肉之精为约束、裹撷，（上、下眼胞为目约裹）筋骨血气之精而与脉并为系，（众精
并脉，以系于目）上属于脑，后出于项中。又曰∶瞳子黑眼法于阴，白眼赤脉法于阳，故
阴阳合，转而精明也。观是论，则后人诊眼疾而分五轮八廓者，盖本乎此。其所
云气轮者，金精之腾结也，即经所谓窠气之精为白眼。白眼属肺，肺主气，故曰气
轮。肺在行为金，金至坚，故白珠独坚实。风轮者，木精之腾结也，即经所谓筋之
精为黑眼。黑眼属肝，肝主筋，在行为木而应风，故曰风轮。风性动，故黑睛左右
不定而色带青也。血轮者，火精之腾结也，即经所谓血之精为络。络属心，心主血，
故曰血轮。心在行为火，火有君、相两种，故岐分于两角，无正轮也。肉轮者，土
精之腾结也，即经所谓肌肉之精为约束、裹撷。属脾，脾主肌肉，故曰肉轮。脾在
行为土，土包万物，该四脏。四脏皆为裹束，故开则动而万用，闭则静而万寂矣。
水轮者，水精之腾结也，即经所谓骨之精为瞳子。瞳子属肾，肾主骨，在行为水，
故曰水轮。水为天一之精，故独得居中。内有大络六，以通心、肺、脾、肝、肾、
命门；中络六，以通胆、胃、大小肠、三焦、膀胱；外有小细之络，莫知其数。（其
络向明，视之了了可数，即禽兽异类，皆有此也。）皆血贯于脑，下连脏腑，通畅血气，往来以滋于
目。故凡病目，则有形色经络显见，而可验内之何脏何腑受病。外有二窍以通其气，
内涵诸液，出而为泪。更有神膏、神水、神光、真气、真精，皆滋目之源液也。神
膏者，目内包涵膏液，破则黑稠水出，由胆中渗润精汁积成，涵养瞳神，衰则有损。
神水者，由三焦发源，先天真一之气所化。在目之内，不可得见。触物损破，则见
黑膏，形如稠痰。在目之外者，即目上润泽之水也。水衰，则有火胜燥暴之患。水
竭，则有目轮大小之疾。耗涩，则有昏眇之危。亏者多，盈者少。神光者，目自视
之精华也。心火发源，胆火用事。夫神之于人也亦大矣，不独一视为然。即行走执
捉，言笑听闻，无神宰率，则块然一形而已。真血者，职藏在肝，升以滋目，指五
脏六腑经络之血，非肌腠散漫之血，故曰真也。真气者，以经络滋养，必先气 而
后血濡，即发生真一之元气也。真精者，即先后二天，真元化汁，根于肾，施于胆，
以及瞳仁之精也。凡此数者，一有所损，则目病矣。大概目形圆而长，外有坚壳数
重，中含清脆，内包神膏。膏外神水，水外皆血。血以滋水，水以滋膏。膏内一点
黑莹，即是肾胆所聚之精华也。唯此一点，空明净彻，烛照无穷，是曰水轮。然必
三者具而后灵明全，三即胆汁、肾精、心神也。五轮足而外应溥，五即气、风、血、
肉、水也。合之浑然，分之井然。水为体，火为用。气为运动，神为维持。妙合阴
阳，光同日月。午前小，午后大，随天地之盈亏。男左胜，女右胜，别阴阳之禀赋。
至若刚柔寿夭，诈直智愚，皆能以目验知。神哉宝乎。更有八廓，其说以八卦八方，
内配脏腑，分别经络，似亦有理。前五轮说中已悉其义，今不更赘。惟录八廓之名，
以备考证。一曰传送廓，应乾卦，位居西北，络通大肠而属肺。二曰津液廓，应坎
卦，位居正北，络通膀胱而属肾。三曰会阴廓，应艮卦，位居东北，络通上焦而配
属命门。四曰清净廓，应震卦，位居正中，络通胆而属肝。五曰养化廓，应巽卦，
位居东南，络通中焦而配属肝络。六曰胞阳廓，应离卦，位居正南，络通小肠而属
心。七曰水谷廓，应坤卦，位居西南，络通胃而属脾。八曰关泉廓，应兑卦，位居
正西，络通下焦而配属肾络。以六配八，余二无配。重肝络、肾络配之者，盖目根
源于肾，专窍于肝，故较他脏为独胜焉。以上五轮八廓之生成配合也。知此，则知
内伤者，内动脏气，灾及五轮。外感者，不从脏变，外邪先袭于络，由络及廓，由
廓及轮。故内伤见证，不肿不痛，痛亦不甚。或视物渐觉不明，或遇晚即为 瞀，
（俗名鸡盲，亦名雀目。）或羞明畏日，或不能久视远视，或涩不欲开，或眼胞收小，或倒睫
拳毛，或青翳白膜，或白珠黄色、黑睛蓝色，或瞳仁散大，或紧小，或欹侧，或两
脂糊，或弦烂，或泪流，或视物以一为二、以红为白、以正为斜，以曲为直，种
种由渐而成者，属内伤。脏也，阴也。外感见证，则发如风火，痒痛不堪。或中如
砂石，或外见疮疡，或脂泪不时，或星障卒起，或向天日如针刺，或近灯烛如火烘，
或兼鼻塞齿疼，或兼身热头痛。种种卒暴而来者，属外感。腑也，阳也。是故病腑
者易愈，病脏者难瘳。脏则视其何脏何因，腑则视其何邪何络而后调之、散之、补
之、泻之。温凉升降，在圆机者自为斟酌也。选方。
《灵枢·大惑论》说：五脏六腑的精气，都向上灌注于眼睛，从而形成眼的精气。精气的汇聚处就是眼窝（窠，指窝穴。聚集精气形成窝穴，有搏结凝聚的意思）。骨的精气表现为瞳仁，筋的精气表现为黑眼球，血的精气表现为血络（包括大小赤脉），气聚在眼窝处的精气表现为白眼，肌肉的精气表现为眼睑（上下眼睑称为目约裹）。筋骨血气的精气与血脉结合成为目系（各种精气并入血脉，以联系于眼睛），向上连接脑部，向后出于颈项中。又说：瞳仁和黑眼球效法阴，白眼和赤脉效法阳，所以阴阳调和，眼睛转动时就能目光明亮。观察这篇论述，那么后人诊断眼疾时划分的五轮八廓理论，大概就源于此。
文中所说的“气轮”，是金精的升腾凝结，即经文中所说的“气聚在眼窝处的精气表现为白眼”。白眼归属于肺，肺主气，所以叫气轮。肺在五行中属金，金性至坚，所以白眼球特别坚实。“风轮”，是木精的升腾凝结，即经文中所说的“筋的精气表现为黑眼球”。黑眼球归属于肝，肝主筋，在五行中属木而应和风，所以叫风轮。风性主动，所以黑眼球左右不定且颜色带青。“血轮”，是火精的升腾凝结，即经文中所说的“血的精气表现为血络”。血络归属于心，心主血，所以叫血轮。心在五行中属火，火有君火、相火两种，所以分布于两眼角，没有正对的眼轮。“肉轮”，是土精的升腾凝结，即经文中所说的“肌肉的精气表现为眼睑”。归属于脾，脾主肌肉，所以叫肉轮。脾在五行中属土，土包容万物，涵盖其他四脏。其他四脏都被包裹束缚，所以睁开时运动而功能万千，闭合时静止而万籁俱寂。
“水轮”，是水精的升腾凝结，即经文中所说的“骨的精气表现为瞳仁”。瞳仁归属于肾，肾主骨，在五行中属水，所以叫水轮。水是天一之精，所以独得居于中央。内部有大络六条，以连通心、肺、脾、肝、肾、命门；中间有络六条，以连通胆、胃、大小肠、三焦、膀胱；外部有小细络，数量不知有多少。（这些络脉面向光亮处看，清晰可数，即使是禽兽异类也有此结构。）这些络脉都贯通于脑，向下连接脏腑，通畅气血，往来滋养眼睛。所以凡是眼病，都会有形色经络显现，从而可以验证内部哪个脏腑受病。外部有两个窍孔以通其气，内部蕴含各种液体，排出后成为泪液。更有神膏、神水、神光、真气、真精，都是滋养眼睛的源液。
神膏，是指眼内包含的膏状液体，破裂则有黑稠水流出来，由胆中渗润的精汁积聚而成，涵养瞳神，若衰弱则会有损伤。神水，由三焦发源，由先天真一之气所化生。在眼内不可见。若触物损破，则可见黑膏，形状像浓痰。在眼外的，就是滋润眼目的水分。水衰弱，就有火胜燥暴的祸患；水枯竭，就有眼轮大小形态的疾病；水耗涩，就有昏花视力的危险。亏损的多，充盈的少。
神光，是眼睛视觉的精华。发源于心火，由胆火发挥作用。神对于人来说也很重要，不单单体现在视物上。即使行走拿取、言笑听看，如果没有神的统率，也不过是一具死板的身躯罢了。真血，职能藏在肝，上升以滋养眼睛，指的是五脏六腑经络中的血，不是肌腠间散漫的血，所以叫真血。真气，依靠经络滋养，必先有气而后有血濡养，即发生真一的元气。真精，即先后天，真元化生的汁液，根源于肾，施用于胆，以及到达瞳仁的精气。凡是有其中一项受损，眼睛就会生病。
大致来说，眼睛形状圆而长，外层有几重坚硬的壳，内含清脆物质，内包神膏。膏外有神水，水外皆是血。血以滋养水，水以滋养膏。膏内有一点黑亮晶莹之物，就是肾胆所聚的精华。唯有这一点，空明净彻，照耀无穷，这就是水轮。然而必须三者具备，灵性光明才完整，所谓三，即胆汁、肾精、心神。五轮齐全，外部对应广泛，所谓五，即气、风、血、肉、水。合起来浑然一体，分开来井然有序。水为体，火为用。气为运动，神为维持。巧妙融合阴阳，光芒如同日月。午前瞳孔小，午后瞳孔大，随天地盈虚变化。男性左眼优势，女性右眼优势，区别阴阳禀赋。至于刚柔寿夭、欺诈正直、智慧愚笨，都能通过眼睛查验知晓。真是神奇宝贵啊。
另外还有八廓，其说法是以八卦八方，内部配合脏腑，分别经络，似乎也有道理。前五轮的说法中已经详尽阐述了其义理，现在不再赘述。只记录八廓的名称，以备考证。第一叫传送廓，对应乾卦，位居西北，络脉连通大肠而归属于肺。第二叫津液廓，对应坎卦，位居正北，络脉连通膀胱而归属于肾。第三叫会阴廓，对应艮卦，位居东北，络脉连通上焦而配属命门。第四叫清净廓，对应震卦，位居正中，络脉连通胆而归属于肝。第五叫养化廓，对应巽卦，位居东南，络脉连通中焦而配属肝络。第六叫胞阳廓，对应离卦，位居正南，络脉连通小肠而归属于心。第七叫水谷廓，对应坤卦，位居西南，络脉连通胃而归属于脾。第八叫关泉廓，对应兑卦，位居正西，络脉连通下焦而配属肾络。以六配八，余下两个无配。重复使用肝络、肾络来配属的，是因为眼睛根源在于肾，专窍于肝，所以比其他脏腑更为突出。以上是五轮八廓的生成配合。
懂得这些，就知道内伤者，是内脏之气内动，灾祸波及五轮。外感者，不从脏腑病变，外邪先侵袭络脉，由络及廓，由廓及轮。所以内伤的表现，不肿不痛，即使痛也不严重。或者看东西逐渐不清楚，或者到了晚上就失明（俗称鸡盲，也叫雀目），或者畏光怕日，或者不能久视远视，或者干涩不想睁眼，或者眼睑收缩变小，或者倒睫拳毛，或者青翳白膜，或者白珠发黄、黑睛发蓝，或者瞳仁散大，或者紧缩变小，或者倾斜偏侧，或者两眼被脂糊住，或者眼角溃烂，或者流泪，或者视物一个看成两个、红色看成白色、直的看成斜的、弯的看成直的，种种逐渐形成的症状，属于内伤。涉及脏，属阴。
外感的表现，则发作如风火般急骤，痒痛难忍。或者眼中感觉像有砂石，或者外面出现疮疡，或者眼泪油脂不时流出，或者星障突然兴起，或者看向太阳像针刺一样，或者靠近灯火像火烤一样，或者兼有鼻塞牙疼，或者兼有身体发热头痛。种种突然暴发的症状，属于外感。涉及腑，属阳。所以病在腑的容易治愈，病在脏的难以痊愈。治脏则看是哪个脏、什么原因，治腑则看是什么邪气、哪条络脉，然后进行调理、发散、补益、泻除。温凉升降，全凭精通医理的人自行斟酌。选方。
The *Ling Shu* (Spiritual Pivot), chapter "Da Huo Lun" (Treatise on Great Confusion), states: The essence and qi of the five zang organs and six fu organs all ascend to pour into the eyes, thereby forming the essence of the eyes. The gathering place of this essence is the eye socket (Ke, meaning a hollow or窝; it refers to the gathering and condensing of essence to form a cavity). The essence of bone manifests as the pupil (Tongzi); the essence of sinews manifests as the black part of the eye (Heiyan, i.e., iris/cornea area); the essence of blood manifests as the collaterals (Lu, including major and minor red vessels); the essence of qi gathered in the eye socket manifests as the white part of the eye (Baiyan); and the essence of muscle manifests as the constraints and wrapping (Yueshuo, Guoxie, referring to the upper and lower eyelids). The essence of sinew, bone, blood, and qi combines with the meridians to form the visual system (Mu Xi) (various essences merge with blood vessels to connect to the eye), ascending to connect with the brain and exiting posteriorly at the nape of the neck. It further states: The pupil and black part follow Yin, while the white part and red vessels follow Yang. Thus, when Yin and Yang harmonize, the eyes rotate and become bright and clear. Observing this treatise, the theory of Five Wheels (Wu Lun) and Eight Palaces (Ba Kuo) used by later generations for diagnosing eye diseases likely originates from here.
The so-called "Qi Wheel" (Qi Lun) is the rising and condensation of Metal Essence, which corresponds to the scripture's statement that "the essence of qi in the socket manifests as the white part." The white part belongs to the Lung (Fei), which governs Qi, hence it is called the Qi Wheel. In the Five Elements, the Lung belongs to Metal, which is extremely hard, thus the sclera is particularly firm. The "Wind Wheel" (Feng Lun) is the rising and condensation of Wood Essence, corresponding to "the essence of sinews manifests as the black part." The black part belongs to the Liver (Gan), which governs sinews, belongs to Wood in the Five Elements, and corresponds to Wind, hence it is called the Wind Wheel. Since Wind nature is moving, the cornea/iris is indeterminate in position and has a bluish-green color. The "Blood Wheel" (Xue Lun) is the rising and condensation of Fire Essence, corresponding to "the essence of blood manifests as collaterals." The collaterals belong to the Heart (Xin), which governs Blood, hence it is called the Blood Wheel. In the Five Elements, the Heart belongs to Fire, which has two types: Ministerial Fire and Sovereign Fire, hence it is distributed at the two corners of the eyes without a central wheel. The "Flesh Wheel" (Rou Lun) is the rising and condensation of Earth Essence, corresponding to "the essence of muscle manifests as the constraints and wrapping." It belongs to the Spleen (Pi), which governs muscle, hence it is called the Flesh Wheel. In the Five Elements, the Spleen belongs to Earth, which encompasses all things and covers the other four zang organs. Since the four zang organs are wrapped and bound, when open, they move and perform myriad functions; when closed, they are still and silent.
The "Water Wheel" (Shui Lun) is the rising and condensation of Water Essence, corresponding to "the essence of bone manifests as the pupil." The pupil belongs to the Kidney (Shen), which governs bone and belongs to Water in the Five Elements, hence it is called the Water Wheel. Water is the essence of Tian Yi (One Heaven), so it uniquely occupies the center. Internally, there are six large collaterals connecting to the Heart, Lung, Spleen, Liver, Kidney, and Mingmen (Gate of Life); six middle collaterals connecting to the Gallbladder, Stomach, Large Intestine, Small Intestine, Sanjiao (Triple Burner), and Bladder; and externally, numerous tiny fine collaterals of unknown number. (These collaterals are clearly visible when facing light, even in birds and beasts.) All these collaterals penetrate the brain, connect downward to the zang-fu organs, circulate Qi and Blood, and nourish the eyes through their flow. Therefore, in any eye disease, changes in color, shape, and collaterals become visible, allowing one to verify which internal zang or fu organ is diseased. Externally, there are two apertures to vent Qi, containing various fluids internally that exit as tears. Furthermore, there are Shen Gao (Divine Paste), Shen Shui (Divine Water), Shen Guang (Divine Light), Zhen Qi (True Qi), and Zhen Jing (True Essence), all of which are source fluids nourishing the eye.
Shen Gao refers to the paste-like fluid contained within the eye; if ruptured, thick black fluid flows out. It is formed by the accumulation of refined juices seeping from the Gallbladder, nurturing the pupil spirit; if deficient, damage occurs. Shen Shui originates from the Sanjiao, transformed by the primordial True One Qi of congenital origin. It is invisible inside the eye. If damaged by contact, black paste resembling thick phlegm becomes visible. Outside the eye, it is the moistening water. If Water is deficient, there is a risk of Fire excess causing dryness and agitation; if Water is exhausted, there are deformities of the eye wheels; if Water is consumed and dry, there is danger of dim vision. Deficiency is common, abundance is rare.
Shen Guang is the essence of visual perception. It originates from Heart Fire and operates through Gallbladder Fire. Spirit (Shen) is great in humans, not limited to vision. Even walking, grasping, speaking, laughing, listening, and hearing require the governance of Spirit; otherwise, the body is merely a lifeless form. True Blood (Zhen Xue) resides in the Liver, ascending to nourish the eyes. It refers to the blood in the five zang and six fu organs and meridians, not the scattered blood in muscles and skin, hence called "True." True Qi (Zhen Qi) is nourished by meridians; Qi must precede Blood for nourishment, representing the generated primordial Yuan Qi. True Essence (Zhen Jing) is derived from postnatal and prenatal sources, transformed from True Yuan into fluid, rooted in the Kidney, applied to the Gallbladder, and reaching the essence of the pupil. If any of these are damaged, eye disease arises.
Generally, the eye is round and elongated, with several layers of hard shell externally, containing crisp clarity internally, and enclosing Shen Gao. Outside the paste is Shen Shui, and outside the water is Blood. Blood nourishes Water, and Water nourishes Paste. Inside the paste is a small, dark, bright spot, which is the concentrated essence of the Kidney and Gallbladder. Only this spot is empty, bright, pure, and illuminating infinitely, known as the Water Wheel. However, only when these three (Gallbladder bile, Kidney essence, Heart spirit) are present is full spiritual clarity achieved. When the Five Wheels are complete, external correspondence is extensive (Qi, Wind, Blood, Flesh, Water). Together they are seamless; separately, they are orderly. Water is the substance, Fire is the function. Qi is movement, Spirit is maintenance. They subtly combine Yin and Yang, their light resembling sun and moon. Pupil size is smaller in the morning and larger in the afternoon, following heavenly and earthly waxing and waning. Males tend to have stronger left eyes, females right eyes, distinguishing yin-yang endowment. Rigidity/flexibility, longevity/shortness of life, deceit/honesty, wisdom/foolishness can all be verified by the eyes. Truly miraculous and precious.
There are also Eight Palaces (Ba Kuo). This theory uses the Eight Trigrams and eight directions, internally matching zang-fu organs and differentiating meridians, which seems reasonable. The meanings were fully explained in the Five Wheels section above, so no further elaboration is needed here. Only the names of the Eight Palaces are recorded for verification. 1. Chuan Song Kuo (Palace of Transmission), corresponding to Qian Trigram, located northwest, connecting to Large Intestine and belonging to Lung. 2. Jin Ye Kuo (Palace of Fluids), corresponding to Kan Trigram, located north, connecting to Bladder and belonging to Kidney. 3. Hui Yin Kuo (Palace of Meeting Yin), corresponding to Gen Trigram, located northeast, connecting to Upper Jiao and matching Mingmen. 4. Qing Jing Kuo (Palace of Purity), corresponding to Zhen Trigram, located center, connecting to Gallbladder and belonging to Liver. 5. Yang Hua Kuo (Palace of Nourishment and Transformation), corresponding to Xun Trigram, located southeast, connecting to Middle Jiao and matching Liver collateral. 6. Bao Yang Kuo (Palace of Womb Yang), corresponding to Li Trigram, located south, connecting to Small Intestine and belonging to Heart. 7. Shui Gu Kuo (Palace of Water and Grain), corresponding to Kun Trigram, located southwest, connecting to Stomach and belonging to Spleen. 8. Guan Quan Kuo (Palace of Gate Spring), corresponding to Dui Trigram, located west, connecting to Lower Jiao and matching Kidney collateral. Matching six to eight leaves two unmatched. Repeating Liver and Kidney collaterals is because the eye root originates in Kidney and specializes in Liver, making them superior to other zang organs. These describe the generation and pairing of Five Wheels and Eight Palaces.
Knowing this, one understands that internal injuries involve internal movement of zang Qi, affecting the Five Wheels. External invasions do not originate from zang transformation; external pathogens first attack the collaterals, then pass from collaterals to palaces, and from palaces to wheels. Thus, internal injury manifestations show no swelling or pain, or pain is slight. Vision may gradually blur, night blindness (Ji Mang, Que Mu) may occur, photophobia may arise, inability to focus on distant objects, dryness preventing opening, eyelid shrinking, trichiasis (Dao Jie Quan Mao), green nebula/white membrane, yellow sclera/blue cornea, dilated or constricted pupils, tilted eyes, greasy discharge, angular cheilitis/ulceration, tearing, diplopia (seeing one as two), color distortion (red as white), straight as slanted, curved as straight—these gradual symptoms belong to internal injury, involving zang and Yin.
External invasion manifestations appear suddenly like wind and fire, with unbearable itching and pain. Sensation of sand in the eye, external ulcers, frequent oily tears, sudden onset of astigmatism/star nebula, stinging sensation looking at sun, burning sensation near lamps, accompanied by nasal congestion/toothache or fever/headache—these sudden symptoms belong to external invasion, involving fu and Yang. Therefore, diseases of fu organs are easy to cure, while diseases of zang organs are difficult to heal. For zang diseases, examine which zang and cause; for fu diseases, examine which pathogen and collateral, then regulate, disperse, tonify, or drain. Warmth, cooling, ascending, descending depend on the judgment of skilled practitioners. Select formulas.