The optical system disclosed in the embodiment includes first to third lenses disposed along an optical axis from an object side toward a sensor side, the optical system satisfies 40° ≤ FOV ≤ 50°, an object-side surface and a sensor-side surface of the first lens are spherical, the first lens has a meniscus shape convex toward the object side, the first lens satisfies: 1.7 ≤ nt_1 ≤ 2.3 and 0.15 ≤ D_1 / TTL ≤ 0.3, TTL satisfies: ≤ 9mm (nt_1 is the refractive index of the first lens, TTL is a distance in the optical axis from an object-side surface of the first lens to an image surface of the image sensor, D_1 is the thickness of the first lens at the optical axis, and FOV is the field of view of the optical system.).