A lens that can be used in a digital camera includes in sequence a first lens element (20), a second lens element (30), a third lens element (40), and a fourth lens element (50). The first lens element is biconvex, and includes a first aspheric surface (22) and a second aspheric surface (24). The second lens is biconcave, and includes a third aspheric surface (32) and a fourth aspheric surface (34). The third lens element is concavo-convex, and includes a fifth aspheric surface (42) and a sixth aspheric surface (44). The fourth lens element includes a seventh aspheric surface (52) and a eighth aspheric surface (54), the seventh aspheric surface and the eighth aspheric surface being wavelike. All of the lens elements are made from plastic. The lens is light, has strong impact resistance, and provides good image quality.

 
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