A daruma with only one eye filled in is not unfinished. It represents a wish that has not yet been fulfilled.
In the best-known form of this custom, you first fill in one eye when you make a wish or set a goal. Then, when the wish comes true or the goal is achieved, you fill in the other eye. The change from one eye to two creates a visible division between the moment the wish was made and the moment it was fulfilled.
Not every Japanese person uses a daruma for wishes in everyday life, but many people still know what the custom means. One of the most familiar examples appears during elections. A candidate may keep a daruma with one eye filled in at the campaign office, then add the second eye after winning. Even people who have never used a daruma themselves may therefore recognize the basic idea: one eye means the goal is still in progress, while two eyes mark its achievement.
There is no need to see a one-eyed daruma as unlucky or disturbing. It is deliberately left that way because the wish is still active. Keeping it somewhere visible can also serve as a reminder of what you hoped to achieve.
The details are not identical everywhere. The order in which the eyes are filled, what people do if the wish is not fulfilled, and other customs can vary by region, temple, or tradition. Some daruma are also sold with both eyes already filled in.
A daruma with one eye is not missing something. It is waiting for the day when the second eye can be added.
