An optical lens, in order from an object side to an image-forming side, includes: a first lens having negative refractive power, a second lens having positive refractive power, a third lens having positive refractive power, a fourth lens having refractive power, and a fifth lens having refractive power. The fourth lens may be positive refractive power, or the fourth lens may have a fourth object-side surface which curves toward the image-forming side. The fifth lens may be negative refractive power, and a spacing may be between the fourth lens and the fifth lens.