Freckles are very common on the face, and there are two main reasons for them: 1. Freckles are an autosomal dominant disease, and the genetic factor plays a very important role, almost every freckle patient has a family history of freckles. 2. The occurrence of freckles is very much related to sun exposure, especially the ultraviolet rays in sunlight, so many freckle patients have a rash that is more obvious in summer and lighter in winter. That is to say, these side effects prove that UV rays play a big role in the occurrence of freckles. For freckles, at present, the main treatment method is laser or intense pulsed light, and the effect is very good.