The origin. A forbidden & secret romance.
It was love at first sight when the Prince of Wales, who would eventually become King George IV of England, first lay eyes on the twice widowed commoner Maria Fitzherbert in 1784 at the opera. The Prince was prohibited by British law to wed Maria because she was a Catholic. According to history, George and Maria were secretly married and exchanged miniatures of one another's eyes, they were made of watercolor paintings on ivory and adorned with gems as a symbol of their love. The identity of the lovers was maintained because each miniature only portrayed one eye.
However, the displays of devotion weren't just given out to covert lovers. According to Graham C. Boettcher's article "Love Never Dies," men frequently had their eyes painted for their wives and lovers to wear since the early 18th century as a way of keeping an eye on them. Moreover, for letting other suitors know that their women were already taken.
The lovers eye fascinated people with great mystery. There is so much depth in mysteries, whether they are made up or genuine, fully realized or only hinted at. They enable us to divert our attention from our own problems, arouse our curiosity, and experience the sense of realization and accomplishment that come from transforming facts into insightful narrative.