内经云。五脏六腑之精皆上注于目。目系则上入于脑。脑为髓海。髓之精为瞳子。
凡病至危。必察两目。视其目色以知病之存亡也。故观目为诊法之首要。凡开目欲见人
者阳症。闭目不欲见人者阴症。目瞑者鼻将衄。目暗者肾将枯。目白发赤者血热。目白
发黄者湿热。目眵多结者肝火上盛。目睛不和者热蒸脑系。目光炯炯者燥病。燥甚则目
无泪而干涩。目多昏蒙者湿病。湿甚则目珠黄而 烂。眼胞肿如卧蚕者水气。眼胞上下
黑色者痰气。怒目而视者肝气盛。横目斜视者肝风动。阳气脱者目不明。阴气脱者目多
瞀。目清能识人者轻。睛昏不识人者重。阳明实症可治。少阴虚症难治。目不了了。尚
为可治之候。两目直视。则为不治之疾。热结胃腑。虽日中亦谵语神昏。目中妄有所见
。热入血室。惟至夜则低声自语。目中如见鬼状。瞳神散大者元神虚散。瞳神缩小者脑
系枯结。目现赤缕。面红娇艳者。阴虚火旺。目睛不轮。舌强不语者。元神将脱。凡目
有眵有泪。精采内含者。为有神气。凡病多吉。无眵无泪。白珠色蓝。乌珠色滞。精采
内夺。及浮光外露者。皆为无神气。凡病多凶。凡目睛正圆及目斜视上视。目瞪目陷。皆
为神气已去。病必不治。惟目睛微定。临时即转动者痰。即目直视斜视上视。移时即如
常者。亦多因痰闭使然。又不可竟作不治论。
【廉勘】肝脉交颠入脑。由脑系而通于目。故肝开窍于目。目则受灵机于脑。脑为
元神之府。故《内经》曰。头倾视深。精神将夺。俞氏以观目为诊法之首要。洵得诊断
学的主脑。盖因神以心为宅。以囟为门。而其所出入之窍。得以外见者惟目。以心脉上
连目系。而目系上通于脑。故瞳神散大者。心神虚散。目不了了者。脑被火燥。目眶陷
下者。脑气虚脱。目瞪直视者。脑髓无气。又兼舌强不语者。脑与心神气俱脱。故昏厥
如尸。王清臣《医林改错》曰。脑髓中一时无气。不但无灵机。必死一时。足以发明目
睛定轮。昏厥不语之精义。宋《和剂局
方》。定出至宝、紫雪两方。一以犀、玳、麝香为君。一以犀、羚、麝香为君。诚得治
脑之要诀。以犀、羚、玳瑁。虽皆为异类通灵之品。而实有清脑退炎之功。麝香尤足
兴奋神经。而为壮脑提神之要药。彼诋中医无治脑之法者。真可谓门外汉矣。
《黄帝内经》说：五脏六腑的精气都向上灌注于眼睛。目系（连接眼球与脑的脉络）则向上进入脑部。脑是髓海（精髓汇聚之处）。髓中的精气表现为瞳仁。
凡是病情危重的，必须观察双眼。通过查看眼睛的颜色来了解疾病的生死预后。所以观察眼睛是诊断方法中的首要步骤。凡是睁眼想要看人的，属于阳证；闭眼不想看人的，属于阴证。眼睛闭合者，鼻子即将出血；眼睛昏暗者是肾脏精气将枯竭；眼白发红的是血热；眼白发黄的是湿热；眼屎多且结块的是肝火过盛；眼球转动不协调的是热邪熏蒸目系；目光炯炯有神的是燥病；燥邪严重则眼睛无泪而干涩；眼睛经常昏蒙不清的是湿病；湿邪严重则眼珠发黄且溃烂；眼睑肿胀像卧蚕一样的是水气停聚；眼睑上下发黑的是痰气阻滞；瞪大眼睛注视的是肝气亢盛；眼球横斜直视的是肝风内动；阳气脱失者眼睛视物不明；阴气脱失者眼睛经常视物模糊错乱。眼神清澈能识别人的病情轻；瞳孔昏花不能识别人的病情重。阳明腑实证可以治疗；少阴虚寒证难以治疗。眼睛视物模糊不清，还是可治的情况；两眼直视不动，就是不治之症。热邪结聚在胃腑，即使在中天也出现胡言乱语、神志昏迷，眼中看到虚幻的景象；热邪侵入血室，只有到了夜晚才低声自语，眼中好像看到鬼怪的样子。瞳孔散大的是元神虚散；瞳孔缩小的是目系枯结。眼睛出现红血丝，面色红润娇艳的是阴虚火旺；眼球转动失灵，舌强直不能说话的是元神即将脱失。凡是眼睛有眼屎有眼泪，神采内敛的，是有神气的表现，大多病情吉利；没有眼屎没有眼泪，眼白颜色发蓝，黑眼珠色泽晦滞，神采被剥夺，以及浮光外露的，都是无神气的表现，大多病情凶险。凡是眼球正圆、或斜视上视、瞪眼、眼窝凹陷的，都是神气已去，疾病必定无法治愈。只有眼球微微固定，但临时又能转动的，是痰证；即使是眼球直视、斜视、上视，过一会儿又像正常一样的，也多是因为痰浊闭塞所致，又不可以完全当作不治之症论断。
【廉勘】肝脉交会于头顶进入脑部，通过目系与眼睛相通，所以肝脏开窍于眼睛。眼睛从脑部接受灵机（精神意识活动）。脑是元神的府邸。所以《黄帝内经》说：头低垂、眼眶深陷，精神将被夺失。俞氏将观察眼睛作为诊断方法的首要环节，确实抓住了诊断学的核心。因为神以心为宅舍，以囟门为门户，而能够向外显露的孔窍唯有眼睛。因为心脉向上连接目系，而目系向上通达于脑，所以瞳孔散大的是心神虚散；眼睛视物模糊的是脑被火热燥邪所扰；眼眶凹陷的是脑气虚脱；瞪眼直视的是脑髓无气。如果再加上舌强直不能说话，就是脑与心神之气俱脱，所以昏厥如尸体一般。王清任在《医林改错》中说：脑髓中一时没有气，不但没有灵机，必死无疑。这足以阐明眼球固定、昏厥不语的精微义理。宋代《太平惠民和剂局方》制定了至宝丹、紫雪丹两个方剂，一个以犀角、玳瑁、麝香为君药，一个以犀角、羚羊角、麝香为君药，确实得到了治疗脑部疾病的关键诀窍。虽然犀角、羚羊角、玳瑁都属于异类通灵之物，但实际上具有清脑退热的功效。麝香尤其能够兴奋神经，是壮脑提神的要药。那些诋毁中医没有治疗脑部疾病方法的人，真可以说是门外汉了。
The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states: The essence of the five zang organs and six fu organs all ascend and pour into the eyes. The eye system (meridians connecting the eyeballs to the brain) then ascends into the brain. The brain is the sea of marrow. The essence of the marrow manifests as the pupil.
Whenever a disease reaches a critical stage, one must examine both eyes. By observing the color of the eyes, one can ascertain the survival or demise of the disease. Therefore, observing the eyes is the primary method of diagnosis. Those who keep their eyes open and wish to see people have Yang syndromes; those who keep their eyes closed and do not wish to see people have Yin syndromes. Eyes that are closed indicate impending epistaxis (nosebleed); dim eyes indicate that kidney essence is about to be exhausted; red whites of the eyes indicate blood heat; yellow whites of the eyes indicate damp-heat; excessive and clumped eye discharge indicates hyperactive liver fire; incoordination of eye movements indicates heat steaming the eye system; bright and piercing gaze indicates dryness disease; severe dryness results in eyes without tears, feeling dry and rough; frequent visual blurring indicates dampness disease; severe dampness results in yellowing and ulceration of the eyeballs; eyelids swollen like a sleeping silkworm indicate water qi retention; blackness above and below the eyelids indicates phlegm qi obstruction; staring with wide-open eyes indicates hyperactive liver qi; horizontal strabismus or oblique gaze indicates stirring of liver wind; depletion of yang qi results in unclear vision; depletion of yin qi results in frequent visual confusion and distortion. Clear spirit capable of recognizing people indicates a mild condition; dull pupils unable to recognize people indicate a severe condition. Yangming fu excess syndromes are treatable; Shaoyin deficiency cold syndromes are difficult to treat. "Muluoliao" (blurred vision) is still a treatable sign; fixed upward gaze of both eyes indicates an untreatable disease. Heat binding in the stomach fu causes delirium and coma even at noon, with hallucinations seen in the eyes; heat entering the blood chamber causes whispering to oneself only at night, with visions of ghosts in the eyes. Dilated pupils indicate dispersion of primordial spirit; constricted pupils indicate drying and knotting of the eye system. Red threads appearing in the eyes with a ruddy and delicate complexion indicate yin deficiency with hyperactive fire; loss of eye movement coordination with tongue stiffness and inability to speak indicates imminent collapse of primordial spirit. Eyes with discharge and tears, with spirit contained within, possess divine spirit (shen qi), indicating generally auspicious outcomes for diseases. Absence of discharge and tears, blue hue in the whites of the eyes, dullness in the irises, loss of internal spirit, and exposure of floating light indicate absence of divine spirit, suggesting generally ominous outcomes. Eyes that are perfectly round, or deviated upwards/obliquely, staring, or sunken, indicate that divine spirit has departed, and the disease is incurable. However, if the eyes are slightly fixed but move temporarily, it is a phlegm syndrome; even if the eyes are fixed, oblique, or upward-gazing, but return to normal after a while, it is also often due to phlegm closure, and should not be immediately deemed incurable.
[Commentary by Liankan] The liver meridian intersects at the vertex and enters the brain, communicating with the eyes via the eye system; thus, the liver opens into the eyes. The eyes receive spiritual mechanism (ling ji, mental activity) from the brain. The brain is the mansion of the primordial spirit. Therefore, the *Huangdi Neijing* states: "Head drooping and deep-set orbits indicate that spirit is about to be seized." Mr. Yu considers observing the eyes as the primary diagnostic method, truly grasping the core of diagnostics. This is because spirit resides in the heart and uses the fontanelle as its gate, and among the orifices through which it exits and becomes visible externally, only the eyes are prominent. Since the heart meridian connects upward to the eye system, and the eye system connects upward to the brain, dilated pupils indicate dispersion of heart spirit; blurred vision indicates the brain being disturbed by fire and dryness; sunken eye sockets indicate depletion of brain qi; staring and fixed gaze indicates lack of qi in the brain marrow. If accompanied by tongue stiffness and inability to speak, it indicates simultaneous collapse of brain and heart spirit, resulting in coma resembling a corpse. Wang Qingren stated in *Yi Lin Gai Cuo* (Correction of Errors in Medical Works): "If there is no qi in the brain marrow for a moment, not only is there no spiritual mechanism, but death is inevitable instantly." This sufficiently elucidates the profound meaning of fixed eyes, coma, and aphasia. The Song Dynasty *Tai Ping Hui Min He Ji Ju Fang* formulated two formulas: Zhibao Wan (Treasure of Ultimate Efficacy Pill) and Zixue San (Purple Snow Powder). One uses rhinoceros horn, tortoise plastron, and musk as sovereign drugs; the other uses rhinoceros horn, antelope horn, and musk as sovereign drugs. These indeed capture the essential principles for treating brain disorders. Although rhinoceros horn, antelope horn, and tortoise plastron are all products from exotic creatures possessing spiritual properties, they actually have the function of clearing the brain and reducing inflammation. Musk is particularly effective in stimulating nerves and is a crucial drug for strengthening the brain and boosting spirit. Those who disparage Traditional Chinese Medicine for lacking methods to treat brain diseases are truly laymen outside the gate.