During my leisure from reading, I enjoyed dabbling in various miscellaneous arts; this nature had been present since my youth. Thus, regarding Qihuang studies (Traditional Chinese Medicine), I secretly grasped the general principles, though my practice was not yet refined. Occasionally, when examining syndromes and consulting ancient methods, I gradually immersed myself in ophthalmology.

I explored ancient prescriptions, but hundred treatments yielded no effect. Did the ancients deceive me? Or was it due to imprecise selection and inelegant application? Or perhaps there is a secret principle in treating eye diseases that the ancients did not reveal, leading to many pitiable cases of blindness, not just my own son! A certain friend showed me a manuscript copy of an ophthalmology text, claiming it had been kept in his family for generations, though its efficacy had never been tested.

Upon receiving and reviewing it, I saw it was a combined copy of two volumes. The first volume, titled *Yicaoting Ophthalmology Complete Book* (One-Grass-Pavilion Ophthalmology Complete Book), was authored by Mr. Deng Bowang of Qingjiang. It extensively collected prescriptions and discussed subtle details with precision. I already knew it to be a life-saving raft for the blind. The second volume, titled *Yishou Eye [Treatise]* (Heterodoxly Transmitted Eye [Treatise]), presented profound and clear meanings, with beautiful and complete concepts. It seemed transcendent and hidden, beyond ordinary thought. Consequently, I selected prescriptions from the book to treat my son Lie’s eyes. Within ten days, the nebulae dissipated, and his vision returned to normal.

Thereafter, I became even more convinced that this book indeed benefits the world, and suddenly realized its true essence lay here. I then vowed to prepare medicines to distribute to poor blind people. However, due to a change in official post to Huai region, I was too busy to attend to this matter. In the Jisi and Gengwu years, I was ordered to manage salt tax in Jingjiang. My colleague, Mr. Yang, was on the verge of losing his sight. I treated him with medicine, and he recovered his vision immediately, astonishing everyone. From then on, visitors seeking medical treatment came daily. The primary and auxiliary medicines used were the most miraculous prescriptions in this book. However, the cost was considerable. Being poor, I could not afford to prepare them, so I merely compounded a prescription containing only four fen of Calcined Galenite (Lu Ganshi). This proved effective without fail.

When I later transferred to Fujian as an official, I did not mention this to anyone. In the autumn of the Jimao year of the Guangxu era, acting as tax collector in Chong’an, I again treated blind patients with medicine, and the number of cured individuals was too numerous to enumerate. Mr. Nian Ou-zhai of Guangning, who served during the Kangxi reign, had previously lamented the fragmentation of the *Yicaoting* edition and reprinted it. He feared that *Yishou* had no printed edition and might be lost, so he specially commissioned its carving. Two hundred years have passed in a flash until now, and what I obtained was a manuscript copy. Copying errors and misprints were abundant. Trying to verify doubtful points, I searched bookshops everywhere but found nothing. Probably because Nian’s printed editions were scarce, and over time they faded away, especially after enduring war and fire.

Presuming upon my shallow learning, I inferred its intent and sought its meaning, making slight revisions and corrections. For parts I dared not alter, I noted explanations above each item for users to consider. I trust that Mr. Bowang and other sages, as well as future experts in Qihuang studies, will not despise my efforts across these centuries. Alas, I am now old. I regret that neither my studies nor my official career in my youth achieved monumental immortality. Holding this book to benefit the world, one person’s reach is limited, and how many can truly be cured? Moreover, I deeply worry about its eventual loss. Therefore, I planned to have it printed to keep the lineage unbroken. I also appended rare empirical prescriptions obtained from elsewhere, wishing to show them to the world, calling them the "True Essence of Enlightenment" (*Qimeng Zhendi*). Thus, I named this book accordingly, keeping the original names for sections, categorizing them, and handing them to the printers for wide distribution. May all blind people under heaven regain their sight, roaming freely in the bright sun without suffering or pain. This is my humble hope. Although the empirical prescriptions are brief, consisting of only two items, I have tested them a hundred times with success. Their utility is great; readers should not neglect them for being short.

Preface by Hu Songzhiqiao of Guichuan, in the first month of the Renwu year, the eighth year of Guangxu.