It is a complete circle. For example, when you write the first stroke of the word "you", put it first and then one. If the circle is completely drawn, it will be an eye. If a hairspring is used, it will not be an eye. Generally, there can only be one eye in a character. Many people draw many without paying attention when writing. For example, the traditional character "飞" has only one stroke, and there may be many eyes in it.