五轮八廓，既详哉言之矣，是为目之体，未及目之用也。若夫灵明默运，鉴万物，察秋
毫，
则有瞳神在焉。华元化曰∶目形类丸，瞳神居中而向前，犹日月之丽东南而晦西北也。目有
神膏神水神光，真血真气真精，皆滋目之源液也。神膏者，目内包涵膏液，此膏由胆中渗润
精汁，积而成者，故能涵养瞳神，衰则有损。神水者，由三焦发源，先天真一之气所化，目
中润泽之水是也。水衰则有火胜燥爆之患。水竭则有目轮大小之疾，耗涩则有昏 之患，亏
者多而盈者少，故世无全精之目也。神光者，源于命门，通于胆，发于心，火之用事也。火
衰则有昏暝之患，火炎则有焚燎之殃，故衰宜补，炎宜降。心君，主也，通于大 ，故大
赤者，实火也。命门为小心，小心相火也，代君行令，通于小 。小 赤者，虚火也。若君
主拱默，则相火自然清宁矣。真血者，即肝中升运滋目注络之血也，此血非比肌肉间流行之
血也，即天一所生之水，故谓之真也。真气者，目之经络中往来生用之气，乃先天真一发生
之元阳也。真精者，乃先天元气所化之精汁，起于肾，施于胆，而后及瞳神也。凡此数者，
一有所损，目难治矣。大概目圆而长，外有坚壳数重，中则青胞，内包黑稠神膏一函，膏外
则白稠神水，水以滋膏，水外则皆血，血以滋水。膏中一点黑莹，是肾胆所聚之精华。惟此
一点，烛照鉴观，空阔无穷，是为人身之至宝，天地之灵光。或曰，瞳神，水也、气也、血
也、膏也。曰，非也。非水、非气、非血、非膏，乃先天之气所生，后天之气所成，阴阳之
蕴妙，水火之精华。血养水，水养膏，膏养瞳神，气运用，神维持，喻以日月，理固有然。
而午前则小，午后则大，亦随阴阳之运用也。大抵目窍于肝，源于肾，用于心，运于肺，藏
于脾，有大有小，有圆有长，亦由禀受之异也。夫男子右目不如左目精华，女子左目不如右
目光彩，此各得阴阳气分之正也。
云间谢东田先生，精通医理，尝谓余曰∶治目以瞳神为本。瞳神不损，虽翳障满布，不
难逐
时消退。瞳神若损，纵极挽救，亦属徒劳无益。故着此论，以明其关系甚重，不可视为泛常
。尔时互相参究，深受其益。今东田已入仙乡，余亦桑榆日暮，捉笔追思，曷胜寒鸟恋群之
概。
五轮八廓的理论，已经详细论述过了，这是关于眼睛的形体结构，还没有涉及到眼睛的功能作用。至于那种灵明自觉、洞察万物、细察秋毫的能力，则在于瞳神的存在。华元化说：眼睛的形状像球丸，瞳神居于中心且向前突出，就像日月悬挂在东南方而西北方显得昏暗一样。眼睛有神膏、神水、神光，以及真血、真气、真精，这些都是滋养眼睛本源津液的东西。所谓神膏，是指眼内包裹涵育的膏状液体，这种膏是由胆中渗出的精汁，积聚而成的，所以能涵养瞳神，如果衰退就会造成损伤。所谓神水，是由三焦发源，由先天真一之气所化生，是眼中润泽的水液。如果水液衰退，就会有火气胜而燥热爆裂的祸患；如果水液枯竭，就会导致眼球大小异常的疾病；如果耗损涩滞，就会有昏蒙的祸患；亏损的多而充盈的少，所以世上没有完全精纯无缺的眼睛。所谓神光，源于命门，通达于胆，发源于心，属于火的作用。如果火气衰弱，就会有昏暝的祸患；如果火气炎上，就会有焚燎的灾殃，所以衰弱应当补益，炎上应当清降。心君是主宰，通达于大络（此处原文可能有误或指代特定经络，通常指心主血脉），所以大络发红，是实火的表现。命门被称为小心，是相火，代替君主行使命令，通达于小络（同上），小络发红，是虚火的表现。如果君主（心）保持拱默静守的状态，那么相火自然就会清静安宁。所谓真血，就是肝中升运滋润注入眼部脉络的血液，这种血不同于肌肉间流行的血液，它是天一之水所生，所以称为真。所谓真气，是眼睛经络中往来产生作用的元气，乃是先天真一发生之元阳。所谓真精，是先天元气所化生的精汁，起于肾，施用于胆，然后才及于瞳神。凡以上这些，只要有一项受损，眼睛就很难治疗了。大概眼睛圆而长，外面有几层坚硬的壳，中间则是青胞，内部包裹着黑稠的神膏一盒，膏的外面则是白稠的神水，水用来滋润膏，水的外面全是血，血用来滋润水。膏中间的一点黑亮精华，是肾和胆汇聚的精华。只有这一点，能够烛照观察，空阔无穷，这是人身间的至宝，天地的灵光。有人问：瞳神是水吗？是气吗？是血吗？是膏吗？回答说：不是。它既不是水，也不是气，也不是血，也不是膏，而是由先天之气所生，后天之气所成，蕴藏着阴阳的奥妙，凝聚了水火精华。血滋养水，水滋养膏，膏滋养瞳神，气负责运用，神负责维持，用日月来比喻，道理本来就是这样。而且午前瞳神较小，午后瞳神较大，也是随着阴阳的运用而变化。大致来说，眼睛窍应于肝，根源在肾，功能用于心，运作涉及肺，储藏于脾，有大有小，有圆有长，这也是由于禀受不同所致。男子右眼的精华不如左眼，女子左眼的光彩不如右眼，这是因为各自得到了阴阳气分的正位。云间谢东田先生，精通医理，曾经对我说：治疗眼病以瞳神为根本。如果瞳神没有受损，即使翳障布满，也不难按时消退。如果瞳神受损，纵然极力挽救，也属于徒劳无益。所以我撰写这篇论述，以阐明其关系非常重要，不可视为平常之事。当时我们互相参究，深受益处。如今东田先生已去世，我也已是桑榆日暮之年，提笔追思，不胜寒鸟恋群之感。
The theories of the Five Wheels and Eight Palaces have been discussed in detail; these pertain to the physical structure of the eye, but do not yet address its functional use. As for the spiritual clarity that operates silently, reflects all things, and perceives even the finest hairs, this resides in the Pupil Spirit (Tongshen). Hua Yuanhua stated: "The shape of the eye resembles a sphere; the pupil spirit is centered and protrudes forward, just as the sun and moon shine brightly in the southeast while the northwest appears dim." The eye possesses Divine Paste (Shengao), Divine Water (Shengshui), Divine Light (Shenguang), True Blood (Zhenxue), True Qi (Zhenqi), and True Essence (Zhenjing); all of these are fluids that nourish the source of the eye.
Divine Paste refers to the paste-like fluid contained within the eye. This paste is formed by the accumulation of essence juice seeping from the Gallbladder (Dan), thus it can nourish the Pupil Spirit; if it declines, damage occurs. Divine Water originates from the Triple Burner (Sanjiao) and is transformed from the primordial True One Qi of innate constitution; it is the moistening water within the eye. If water declines, fire may prevail, leading to dryness and bursting afflictions. If water is exhausted, diseases of abnormal eye size arise; if consumed and stagnant, there is a risk of dimness; since deficiency is common and fullness is rare, no eye in the world is perfectly pure.
Divine Light originates from the Gate of Life (Mingmen), connects with the Gallbladder, issues from the Heart (Xin), and represents the function of Fire. If fire declines, there is a risk of dimness; if fire flares up, there is a disaster of burning; therefore, decline requires tonification, and flare-up requires descending. The Heart Monarch is the master and connects with the major collaterals; redness in the major collaterals indicates Excess Fire. The Gate of Life is called the 'Small Heart' and represents Ministerial Fire (Xianghuo), which acts on behalf of the ruler and connects with the minor collaterals; redness in the minor collaterals indicates Deficiency Fire. If the Monarch remains still and silent, Ministerial Fire naturally becomes clear and tranquil.
True Blood is the blood rising and transporting from the Liver (Gan) to nourish the eye's collaterals; this blood differs from the blood circulating among muscles and is generated by the Water of Tianyi, hence it is called 'True'. True Qi is the vital energy moving within the eye's meridians to generate function, originating from the primal Yang of the innate True One. True Essence is the essence juice transformed from innate primordial Qi, starting from the Kidney (Shen), applied to the Gallbladder, and finally reaching the Pupil Spirit. If any of these are damaged, the eye becomes difficult to treat.
Generally, the eye is round and elongated, surrounded by several layers of hard shell externally, with the Qing Bao (Green Capsule) in the middle, containing a box of black, thick Divine Paste internally. Outside the paste is white, thick Divine Water, which nourishes the paste. Outside the water is all blood, which nourishes the water. A single point of black brilliance within the paste is the essence gathered by the Kidney and Gallbladder. Only this point allows for infinite illumination and observation; it is the supreme treasure of the human body and the spiritual light of heaven and earth.
Someone asked: Is the Pupil Spirit water? Qi? Blood? Paste? I replied: No. It is neither water, nor Qi, nor blood, nor paste. It is generated by innate Qi and completed by acquired Qi, containing the subtleties of Yin and Yang, and the essence of Water and Fire. Blood nourishes water, water nourishes paste, paste nourishes the Pupil Spirit, Qi manages operation, and Spirit maintains it. Using the sun and moon as metaphors, this principle is inherent. Moreover, the pupil is smaller before noon and larger after noon, also following the operation of Yin and Yang.
Broadly speaking, the eye opens through the Liver, originates from the Kidney, functions through the Heart, operates via the Lung (Fei), and stores in the Spleen (Pi). Its size and shape vary due to different constitutions. In men, the right eye lacks the essence of the left; in women, the left eye lacks the radiance of the right; this is because each obtains the correct aspect of Yin or Yang Qi.
Mr. Xie Dongtian from Yunjian, who was proficient in medical principles, once told me: "Treating eye diseases takes the Pupil Spirit as the root. If the Pupil Spirit is undamaged, even if nebulae cover the eye, they will easily recede in time. If the Pupil Spirit is damaged, even extreme rescue efforts are futile. Therefore, I wrote this treatise to clarify its critical importance, so it should not be regarded as ordinary." At that time, we studied each other's insights and benefited greatly. Now Mr. Dongtian has passed away, and I am in my twilight years. Writing this to recall him, I feel the sorrow of a cold bird longing for its flock.