Abstract: Disclosed is a lens, comprising a lens element which comprises a first sub-lens and at least two second sub-lenses. The second sub-lens has a non-rotationally symmetrical structure, the first sub-lens comprises a first active clear portion, and the second sub-lens comprises a second active clear portion, wherein the second active clear portions of any two second sub-lenses are rotationally symmetrical with respect to an incident axis; the first active clear portion is configured for an incident beam to pass therethrough so as to form a first image on an image side of the lens; and the second active clear portion is configured for the incident beam to pass therethrough so as to form a second image on the image side of the lens, the number of second images being the same number as the number of second active clear portions, and the first image and each second image being spaced apart from each other.