A Daruma doll (だるま) is a hollow, round, Japanese doll that are seen as a symbol of perseverance and good luck, making them a popular gift of encouragement. The eyes of Daruma are often blank. The recipient of the doll fills in one eye upon setting a goal or wish, then the other upon fulfilling it. In this way, every time they see the one-eyed Daruma, they recall the goal.
Should not be confused with quadruple amputee, which will often use the 達磨 tag on pixiv.