Optical lens

An optical lens, comprising a total of six lenses, wherein from an object side to an imaging plane along an optical axis of the optical lens, the optical lens sequentially comprises:

• a first lens with a negative focal power, both an object side surface of the first lens and an image side surface of the first lens being concave;
• a second lens with a negative focal power, an object side surface of the second lens being concave, and an image side surface of the second lens being convex;
• a third lens with a positive focal power, both an object side surface and an image side surface of the third lens being convex;
• a fourth lens with a positive focal power, both an object side surface and an image side surface of the fourth lens being convex;
• a fifth lens with a negative focal power, an object side surface of the fifth lens being concave, and an image side surface of the fifth lens being convex;
• and
• a sixth lens with a positive focal power, an object side surface of the sixth lens being convex, and an image side surface of the sixth lens being concave;
• wherein the fourth lens and the fifth lens are cemented to form a cemented lens;
• an effective focal length f of the optical lens and a true image height IH corresponding to a maximum field of view of the optical lens meet an expression:
• 0.55<f/IH<0.65;
• and
• an aperture HD1 of the object side surface of the first lens corresponding to half of the maximum field of view of the optical lens and an aperture D1 of the object side surface of the first lens corresponding to the maximum field of view meet an expression:
• 0.5<HD1/D1<0.6.