A wide-angle lens includes a first lens group, a second lens group, and an aperture arranged in that sequence from object side to image side. The first lens group as a whole has a positive refractive power, and includes a first lens, a second lens, a third lens, and a fourth lens. The first lens has a negative refractive power. The second lens has a negative refractive power. The third lens has a negative refractive power. The fourth lens has a positive refractive power. The second lens group as a whole has a positive refractive power, and includes a fifth lens, a sixth lens, a seventh lens, and an eighth lens. The fifth lens has a positive refractive power. The sixth lens has a negative refractive power. The seventh lens has a positive refractive power. The eighth lens has a positive refractive power.