Optical lens

An optical lens, comprising:

• a first lens group with negative refractive power and comprising two lenses with refractive power,
• a second lens group with positive refractive power and comprising three lenses with refractive power, one of the three lenses having a diffractive optical surface, and the first lens group and the second lens group being arranged in order from a magnified side to a minified side;
• and
• an aperture stop disposed between the first lens group and the second lens group, wherein the optical lens satisfies the condition:
• |(0.5*IMA)/(EFL*TAN(X))−1|<0.3
• where EFL denotes an effective focal length for visible light, IMA denotes a maximum image circle of an image plane formed at an effective focal length for visible light, and X denotes half of a maximum field of view.

An optical lens, comprising:

• a first lens group with negative refractive power, a number of lenses with refractive power of the first lens group being smaller than three;
• a second lens group with positive refractive power, a number of lenses with refractive power of the second lens group being smaller than five, and the second lens group having a lens with a diffractive optical surface;
• and
• an aperture stop disposed between the first lens group and the second lens group, wherein the optical lens satisfies the condition:
• TTL/IMA<3.3
• where TTL denotes a total track length of the optical lens, and IMA denotes a maximum image circle of an image plane formed at an effective focal length for visible light.