An image lens, in order from an object side to an image side thereof, includes a first lens including a first surface and a second surface, a second lens including a third surface and a fourth surface, a third lens including a fifth surface and a sixth surface, a fourth lens including a seventh surface and a eighth surface, and an image plane. The image lens satisfies the following formulas: D/TTL>1.11; D/L>1.13; Z/Y>0.076; wherein D is the maximum image diameter of the image plane; TTL is a total length of the image lens; L is a distance from an outermost edge of the eighth surface to an optical axis of the image lens; Z is a distance from a central point of the sixth surface to an outermost edge of the sixth surface; and Y is a distance from the outermost edge of the sixth surface to the optical axis.