寒令伤人无火郁，直据大中成冷厥，循经以入渐而深，内邪逼出方发热，热煎既久了无寒，谓从寒变成何说。
风寒伤中本无常，或入于阴或入阳，就向阴阳求活法，初终于足任端详。
此章谓目病因伤寒而得也。夫伤寒百病之祖，不独专责在目。读仲景先生书得其纲领，治亦无难。若求之多
歧则支离矣，略述一二于下。太阳经，表之表也，行身之背。邪入皮毛则先伤之，便有恶寒恶风，头痛脊痛之症。
脉浮紧无汗为伤寒，以麻黄汤发之，得汗为解。浮缓有汗为伤风，桂枝汤，邪散汗止为解。身热者，邪闭元府，
内气不能泄而生，非风寒之所变也。阳明经，表之里也，行身之前。发热恶寒，脉微大而长，鼻干不眠，用葛根
汤以解肌。少阳经，半表半里也，行乎两胁之旁。耳聋，胁痛，口苦，寒热往来，脉弦而数，小柴胡汤和之。过
此为邪入腑，若其脉沉而有力，不恶风寒，而反恶热，谵语大渴，六七日不大便，明其热入肠胃，所谓正阳明病
也。轻者大柴胡汤，重则三承气，大便通而愈矣。过此则少阴、太阴、厥阴，俱
入脏而为里。当辛温对症主治，不可凉散。若初起便恶寒，手足厥冷，或战栗，倦卧不渴，兼之腹痛吐泻，或口
出涎沫，面如刀刮，不发热，而脉沉迟无力，此为阴症，不从阳经传来，轻则附子理中汤、四逆汤，重则九转丹、
回阳饮以温之，不宜少缓。外此有假阴假阳，如太阳症，头痛发热，脉当浮而反沉，又似少阴矣，故用麻黄附子
细辛。少阴症，脉沉，应无热而反发热，又似太阳矣，须用甘草附子干姜。阴症四肢厥冷，而阳症间亦或然，此
四逆汤、四逆散不同也。阴证下利，而阳症亦有漏底，此理中汤与黄龙汤不同也。又有真阴真阳虚损发热，亦与
伤寒无异，如恶寒自汗，胸膈饱闷，则用补中益气汤而愈。面赤口渴烦躁，与六味地黄汤亦得。再，下部恶寒足
冷，或欲饮而反吐，即于前方加肉桂、附子、五味，下咽随安。总之伤寒者，盖冬时严寒，感冒即病之名。先由
皮毛经络而入腑入脏。始虽恶寒发热，而终为热症，其人必素有火者。中寒者，直入脏腑，始终恶寒，而并无发
热等症，其人必无火者。经曰∶发热恶寒者，发于阳也。无热恶寒者，发于阴也。寒伤形，热伤气。一则发表攻
里，一则温中散寒，两门判然明白，那得存骑墙之见，而与素有内伤者，阴阳真假，同证混治耶。目科忽伤寒而
不论，专家论伤寒而迂阔。愿常领会此条，所谓相与观所尚，时还读我书也。
寒邪伤人，若无火郁之象，则直接表现为中焦虚冷导致的四肢厥逆。寒邪沿经络逐渐深入，体内的阴寒之邪逼迫阳气外越才出现发热；若热邪煎熬日久，体内已无寒象，又怎能说这是从寒证转化而来的呢？
风寒侵袭人体本没有固定的规律，有时侵入阴经，有时侵入阳经。应当在阴阳辨证中寻找灵活的治疗方法，初起和终末阶段都要在足部经脉上仔细诊察。
这一章论述的是因伤寒而引发的目病。伤寒是百病的根源，并不仅仅局限于眼部疾病。研读张仲景先生的著作掌握其纲领，治疗也就并不困难。如果追求繁杂的歧路，就会变得支离破碎。以下略述一二要点：
太阳经，是体表的表层，行于背部。邪气侵入皮毛便首先损伤此经，会出现恶寒、恶风、头痛、脊痛等症状。脉象浮紧且无汗的为伤寒，用麻黄汤发汗解表，出汗后即为痊愈。脉象浮缓且有汗的为伤风，用桂枝汤治疗，邪气散去、汗止即为痊愈。身体发热，是因为邪气闭塞了玄府（汗孔），体内正气不能宣泄而生热，并非风寒直接变化所致。
阳明经，是体表的里层，行于身前。出现发热、恶寒、脉象微大而长、鼻干、失眠等症状，用葛根汤解肌发表。
少阳经，处于半表半里之间，行于两胁旁边。出现耳聋、胁痛、口苦、寒热往来、脉象弦数等症状，用小柴胡汤和解少阳。超过这个阶段，邪气传入腑，如果脉象沉而有力，不恶风寒反而恶热，出现谵语、大渴、六七天不大便，说明热邪进入肠胃，这就是典型的阳明病。轻症用大柴胡汤，重症用三承气汤，大便通畅即可痊愈。
超过这个阶段，邪气传入少阴、太阴、厥阴，都进入脏成为里证。应当用辛温药物对症主治，不可使用寒凉发散之法。如果初起就恶寒、手足厥冷，或战栗、疲倦嗜卧、不口渴，兼有腹痛吐泻，或口出涎沫、面色如刀刮般苍白，不发热而脉象沉迟无力，这属于阴证。这不是从阳经传变而来，轻症用附子理中汤、四逆汤，重症用九转丹、回阳饮来温补，不宜稍有迟缓。
除此之外，还有假阴证和假阳证。例如太阳证，头痛发热，脉象本该浮却反而沉，看起来又像少阴证，所以要用麻黄附子细辛汤。少阴证，脉象沉，本应无热却反而发热，看起来又像太阳证，须用甘草附子干姜汤。阴证四肢厥冷，但阳证间或也会出现类似情况，这就是四逆汤与四逆散不同的地方。阴证下利，但阳证也有“漏底”（热结旁流）的情况，这就是理中汤与黄龙汤不同的地方。
又有真阴和真阳虚损导致的发热，也与伤寒无异。如恶寒自汗、胸膈饱闷，用补中益气汤即可痊愈。面赤、口渴、烦躁，用六味地黄汤也能治愈。另外，下部恶寒、足冷，或想喝水却反而呕吐，就在前方中加入肉桂、附子、五味子，服药后随即安宁。
总之，“伤寒”是指冬季严寒时，感冒即发病的名称。邪气先由皮毛经络而入，进而入腑入脏。开始虽然恶寒发热，但最终转为热证，这种人必定素体有火。而“中寒”，则是邪气直入脏腑，始终恶寒，并没有发热等症状，这种人必定素体无火。
经文说：“发热恶寒者，发于阳也。无热恶寒者，发于阴也。”寒邪伤形，热邪伤气。一个是发表攻里，一个是温中散寒，两门界限分明明白，怎么能存有骑墙模棱两可的看法，而与素有内伤的人的阴阳真假、同证混治呢？眼科医生忽然遇到伤寒却不加讨论，专论伤寒的专家又显得迂阔不通。希望经常领会这一条，所谓“相与观所尚，时还读我书也”。
Cold pathogenic factors injuring the human body, if there is no Qi stagnation transforming into fire (Huo Yu), directly present as cold reversal of the limbs (Ling Jue) due to middle jiao deficiency-cold. The cold enters along the meridians and gradually deepens; internal evil forces Yang Qi outward, only then does fever occur. If heat has been simmering for a long time, there is no longer any cold in the interior; how can one claim this transformed from a cold syndrome?
Wind-cold invading the interior has no fixed pattern; it may enter Yin meridians or Yang meridians. One must seek flexible methods within Yin-Yang differentiation, carefully examining the foot meridians at both the initial and terminal stages.
This chapter discusses eye diseases caused by Shang Han (Cold Damage). Shang Han is the ancestor of all hundred diseases, not exclusively limited to the eyes. By studying Mr. Zhang Zhongjing's writings and grasping their principles, treatment becomes manageable. Pursuing complex divergent paths leads to fragmentation. Below are briefly outlined some key points:
The Taiyang Meridian is the exterior of the exterior, running along the back of the body. When evil invades the skin and hair, it injures this meridian first, presenting with aversion to cold, aversion to wind, headache, and spinal pain. A floating and tight pulse without sweat indicates Shang Han (Cold Damage); treat with Mahuang Tang (Ephedra Decoction) to induce sweating; resolution occurs when sweat appears. A floating and moderate pulse with sweat indicates Shang Feng (Wind Injury); treat with Guizhi Tang (Cinnamon Twig Decoction); resolution occurs when evil disperses and sweat stops. Body heat arises because evil closes the Yuan Fu (pores/defensive gateways), preventing internal Qi from venting; this heat is generated internally, not directly transformed from wind-cold.
The Yangming Meridian is the interior of the exterior, running along the front of the body. Symptoms include fever, aversion to cold, slightly large and long pulse, dry nose, and insomnia. Treat with Gegen Tang (Kudzu Decoction) to resolve the muscle layer.
The Shaoyang Meridian is half-exterior and half-interior, running alongside the hypochondrium. Symptoms include deafness, hypochondriac pain, bitter taste in the mouth, alternating chills and fever, and wiry and rapid pulse. Treat with Xiaochaihu Tang (Minor Bupleurum Decoction) to harmonize. Beyond this stage, evil enters the Fu organs. If the pulse is deep and forceful, with aversion to neither wind nor cold but rather aversion to heat, accompanied by delirious speech, intense thirst, and constipation for six to seven days, it indicates heat entering the intestines and stomach, constituting typical Yangming disease. Mild cases use Dachaihu Tang (Major Bupleurum Decoction); severe cases use the Three Chengqi Decoctions (San Chengqi Tangs); recovery occurs upon bowel movement.
Beyond this, evil enters the Zang organs via Shaoyin, Taiyin, and Jueyin, becoming interior syndromes. Treatment should employ acrid-warm herbs targeting specific symptoms; cool and dispersing methods are contraindicated. If initially presenting with aversion to cold, cold reversal of hands and feet, tremors/shivering, fatigue with desire to lie down, absence of thirst, combined with abdominal pain, vomiting, diarrhea, salivation, pale face like scraped knife, no fever, and deep, slow, weak pulse, this is a Yin Syndrome. This did not transmit from Yang meridians. Mild cases use Fuzi Lizhong Tang (Aconite Regulate the Middle Decoction) or Sini Tang (Frigid Extremities Decoction); severe cases use Jiuzhuan Dan (Nine-Turn Pill) or Huiyang Yin (Restore Yang Infusion) to warm; delay is inadvisable.
Outside these, there are false Yin and false Yang syndromes. For instance, Taiyang syndrome presents with headache and fever, but the pulse is deep instead of floating, resembling Shaoyin syndrome; thus, Mahuang Fuzi Xixin Tang (Ephedra, Aconite, and Asarum Decoction) is used. Shaoyin syndrome presents with deep pulse and fever despite typically being afebrile, resembling Taiyang syndrome; thus, Gancao Fuzi Ganjiang Tang (Licorice, Aconite, and Dried Ginger Decoction) is required. Yin syndrome causes cold reversal of limbs, yet Yang syndrome occasionally presents similarly; this distinguishes Sini Tang from Sini San (Frigid Extremities Powder). Yin syndrome involves diarrhea, yet Yang syndrome also presents with "leaky bottom" (heat binding with purgation flow); this distinguishes Lizhong Tang (Regulate the Middle Decoction) from Huanglong Tang (Yellow Dragon Decoction).
Furthermore, true Yin and true Yang deficiency causing fever resembles Shang Han. Aversion to cold with spontaneous sweating and chest/diaphragm fullness resolves with Buzhong Yiqi Tang (Middle-Boosting Qi-Supplementing Decoction). Red face, thirst, and irritability resolve with Liuwei Dihuang Tang (Six-Ingredient Rehmannia Pill). Additionally, lower body aversion to cold with cold feet, or desire to drink followed by vomiting, is treated by adding Rougui (Cortex Cinnamomi), Fuzi (Radix Aconiti Lateralis Preparata), and Wuweizi (Fructus Schisandrae) to the previous formula; relief follows ingestion.
In summary, "Shang Han" refers to illness contracted immediately after exposure to severe winter cold. Evil enters via skin, hair, and meridians, then into Fu and Zang organs. Initially presenting with aversion to cold and fever, it ultimately transforms into a heat syndrome; such individuals inherently possess Fire (excess heat). "Zhong Han" (Mid-Cold) involves evil directly entering Zang and Fu organs, persistently presenting with aversion to cold without fever; such individuals inherently lack Fire. The Classic states: "Fever with aversion to cold originates in Yang. No fever with aversion to cold originates in Yin." Cold injures the Form; Heat injures Qi. One approach releases the exterior and attacks the interior; the other warms the middle and scatters cold. These two categories are clearly distinct. How can one maintain an equivocal view and confuse-treat those with chronic internal injury regarding true/false Yin-Yang and identical-symptom differentiations? Ophthalmologists suddenly encounter Shang Han but do not discuss it; experts discussing Shang Han are often pedantic. I hope you frequently comprehend this section, as stated: "Observe what is valued together, and occasionally read my book."