Abstract: Provided is a camera optical lens including seven lenses sequentially from object side to image side: first lens having negative refractive power, second lens having positive refractive power, third lens having positive refractive power, fourth lens having positive refractive power, fifth lens having negative refractive power, sixth lens having positive refractive power, seventh lens having negative refractive power and with object and image side surfaces being free-form surfaces. Focal length of camera optical lens is f; focal length of first lens is f1, focal length of third lens is f3, focal length of fourth lens is f4; refractive index of third lens is nd3; refractive index of sixth lens is nd6; refractive index of seventh lens is nd7, and following relational expressions are satisfied: ?1.52?f1/f??1.38; 1.56?nd3?1.59; 1.53?nd6?1.81; 1.61?nd7?1.67; 2.04?f3/f4?2.27.

Abstract: A low distortion lens suited for a wide variety of applications uses a double plane symmetry lens as part of a lens system to permit aberration correction to be optimized in the field of view of an associated sensor. Wide angle, Kepler telescopic and Galileo telescopic designs can be implemented. The design can be implemented using existing manufacturing techniques.