|A depiction of Saint Ottilia, with her book showing "restored" eyes.|
In c.1622, Ottilia, according to legend, was born blind, after which she was disowned by her father, and sent to a nearby monastery, during which time, a Saint Erhard, a saint of Regensburg, baptized her “Sol Dei”, meaning “Sun of God” (Ѻ) , in Latin, or Odile in German, after which, at age 12, she recovered her sight.
In c.1785, Goethe took a pilgrimage, of some sort "Mount Sainte-Odile"; the following is a reflection on this:
“I shall always remember with pleasure a pilgrimage to the Ottilienberg (Saint Ottilia's Mount) (Ѻ) which we made in company with about a thousand of the faithful. There, amidst the ruins of a fort built by the Romans, the youthful Ottilia, daughter of a count, had been induced by piety to choose herself a retreat in a rocky cave. Near the chapel in which the pilgrims pay their devotions, is shewn the spring at which she quenched her thirst; and many interesting anecdotes of this pious maiden are related. Her name and the portrait I formed of her in my own mind remained deeply impressed. After long meditating upon it, I at length bestowed this name on one of my beloved daughters, whose pure and religious hearts have secured them a favorable reception in the world.”— Johann Goethe (c.1820), Memoirs 
On 9 May 1809, Goethe sent a letter to Charlotte von Stein, referred to her as “St. Ottilia”. 
On 3 Oct 1809, Goethe published Elective Affinities, wherein the following clue is found:
Quotes | On
The following are quotes on Ottilia:
“St. Ottilia was the blind daughter of the Duke of Alsace. Her father, who was a pagan, commanded that on account of her infirmity she should be left out, and exposed to death. Her nurse then fled to a monastery with the child. Then Erhard, a bishop of Bavaria, was told in a vision that he should go to a certain monastery, where he would find a little girl of noble birth who was blind. He was commanded to baptize her and call her name Ottilia, and promised that her sight should be given her. All this was done according to the vision. Her father repented of his wickedness before his death, and gave her all his wealth. Then Ottilia, knowing that for his cruelty her father was tormented in purgatory, determined to deliver him by prayers and penance. She built a convent at Hoheuburg, of which she was abbess, and there she gathered one hundred and thirty nuns. She is represented in the black Benedictine habit. Her attributes are the palm or crosier, and a book upon which are two eyes. She is patron saint of Alsace, and especially of Strasburg. She is also protector of all who suffer with diseases of the eye. December 13, A. D. 720.”— Clara Erskine (1895), Handbook of Christian Symbols (pg. 248)
1. Goethe, Johann. (c.1820). Memoirs of Goethe, Volumes One-Two (translator: Henry Colburn) (pg. 394). Publisher, 1824.
2. (a) Bielschowsky, Albert. (1911). The Life of Goethe (XII: Die Wahlverwandtschaften, pgs. 347-87; painting, pg. 355; letter, pg. 452). G.P. Putnam’s Sons.
(b) Daxecker, F. and Broucek, A. (1995). “An Image of Saint Ottilia with Reading Stones” (abs), Gesnerus, 52:319-22.
(c) Grossmann, T. (1981). “St. Ottilia, Patron saint of suffers from Eye Diseases: An Unusual Representation with a Cra’s Pincer at the Mercy-Seat Altar in Bad Aussee” (abs), Klin Monbl Augenheikd, 178(6): 480-1.
● Odile of Alsace – Wikipedia.