Han Yu of Changli once said: "If no one precedes it, even if beautiful, it will not be manifest; if no one follows it, even if prosperous, it will not be transmitted." How profound these words are! For thousands of years, the past and present have relied on this continuity. Otherwise, the achievements attained through the painstaking efforts of predecessors would be viewed indifferently by successors, leading to their complete extinction. If one does not inherit the ancient traditions to enlighten future generations, would not the entire world become blind? Therefore, gentlemen who cling to the old and preserve the fragmented pay special attention to lost learning, which is indeed justified.

Sima Qian, upon completing his book, stated in his preface that he intended to "hide it in famous mountains and transmit it to worthy individuals." Alas! How difficult it is to find such individuals? Hu Zhijiao of Guichuan loved learning and admired antiquity; he was versatile in arts and skilled in many abilities. Because he was versatile, he cherished his skills as his life; because he admired antiquity, he feared that ancient knowledge would vanish. His learning and capabilities were like an ocean to me, boundless and unfathomable. Now, I specifically discuss his proofreading and publication of *Qimeng Zhen Di* (The True Essence of Enlightenment). Like taking a scoop of water from a gourd ladle, I wish to explore this with the world. *Qimeng Zhen Di* is the title given by Hu of Guichuan to summarize two famous ophthalmology works. One was written by Mr. Deng Bowang of Qingjiang, titled *Yicaoting Mukke Quanshu* (Complete Book of Ophthalmology at Yicaoting Pavilion), but the original was brief and incomplete. The other, author unknown, was *Yishou Yanke* (Uniquely Transmitted Eye Surgery), which remained in the world, possessing the skill of clearing clouds and the wonder of dispelling fog. During the Kangxi reign, Nian Xiyao promoted the reprinting of Deng's work and initiated the carving of *Yishou Yanke*. Today, despite extensive searching, the original texts cannot be found. What a pity! This learning is on the verge of extinction.

I am naturally eccentric and unrestrained, unwilling to stay confined under a window, having loved traveling for a long time, and having met many scholars and officials. Everywhere I went, I saw brocade-like splendor and abundant treasures, bizarre and dazzling to worldly eyes, everywhere. Yet I viewed them with disdain, my eyes seemingly blind. In fact, I am not blind in sight, but seem so; thus, I know that they are not merely blind in sight, but also blind in heart. How sad! Who has made the ignorant people of the world truly blind?

In the spring of Gengchen year of the Guangxu era, I traveled to Longmian and entered Fujian. The only person I connected with immediately was Hu Guichuan. He arrived at his hall, displaying a few pieces of famous calligraphy and painting, with sparse furnishings, simple and rustic, close to ancient styles. After bowing and sitting down to talk, his demeanor was dignified, and his words were substantial. Retreating afterwards, I was convinced, believing this could open my blindness. Not long after, Hu Guichuan somehow learned of me, warmly invited me to stay at his home, and instructed his young son to study classics under me. Days and months passed, winter and summer alternated twice until now. Initially, when I arrived at the residence, I unexpectedly held him in low regard in my mind, yet was suddenly dazzled by what I saw here. Why was this so? Ascending his hall, there were only books; entering his study, there were only books; resting in his quarters, there were only books. Book cases stood like mountains, shelves filled with scrolls. Compared to the dazzling splendor of brocades and treasures, this was several times more magnificent. Truly, I had seen all beauty, nothing could surpass it. Only after staying there for a long time did I realize that Hu Guichuan was profound in Confucian Classics, familiar with History, well-versed in the Hundred Schools of Thought, and especially deep in Qi-Huang studies (Traditional Chinese Medicine). Moreover, there was something even more extraordinary: he understood astrology, was skilled in Go and Feng Shui, mastered Dragon-Tiger Yang House geomancy, and practiced divination according to Fuxi's methods. He used tortoise shells for Liu Ren divination and was particularly adept at wind-water appraisal. Possessing unique insight, whether judging beauty or ugliness, good or evil, orthodoxy or heterodoxy, auspiciousness or inauspiciousness, everything was revealed without hiding its form. Through Shen Feng (physiognomy/destiny analysis), he could discern the prosperity, adversity, longevity, and early death of the world, summarizing them in the palm of his hand. He had also tried military strategy, serving to suppress rebels in Huxiang. In times of peace, such skills were useless, so Hu Guichuan kept them secret and never spoke of them. All these were essentially the brocades and treasures in Hu Guichuan's chest and abdomen, dazzling and bizarre, far beyond just Qi-Huang studies. Qi-Huang studies were but a drop in the vast ocean. Therefore, what I am currently proofreading and publishing, with sincere and earnest devotion, is solely to continue the lost ancient learning, finding joy in this continuation. Alas! The learning of Bowang and other sages, since being continued from now on, relies entirely on Hu Guichuan, who loves learning, admires antiquity, and is versatile. Without him, how could it be transmitted? To whom could it be entrusted? If this book had fallen into the hands of others who did not cherish it as a treasure, it would have been thrown onto shelves, subject to insect damage and rodent gnawing, or leaking rain and dampness, rotting away, discarded in broken baskets, or thrown into fire and water. Who would have asked about it? Those who knew its value would have hidden it deeply and kept it secret, hoarding it to sell for profit, treating the world's blindness while blinding the world's eyes, making crowds marvel at it as an unprecedented and unparalleled unique skill. This would gain fame, but ultimately lead to the same end. Thus, those who "hide it in famous mountains and transmit it to worthy individuals" are distinct from such people. Now, Hu Guichuan cherishes it greatly and fears it deeply, fearing his art will perish and ancient knowledge will vanish. He has published it to spread it widely throughout the world. The sages like Bowang are not just a momentary glory of their time. Future generations who master these skills and apply them beautifully will take *Qimeng Zhen Di* as their model. By mastering an art, one achieves fame; fame and art will surely be manifest. Alas! Hu Guichuan alone connects the past and future, acting as both successor and predecessor. He truly wishes to use this to prevent the world from blindness. How can the world fathom this? Alas, alas! I am lazy and eccentric, and I wish to proclaim loudly to the world: The blind need not remain blind; those who see should not plunge themselves into blindness. Protect your eyes as you protect your heart.

Preface by Zhang Shouliu, Zhuowo, of Wantong, in the first ten days of the first month of the Renwu year, 8th Year of Guangxu.