In a lens module, a sidewall of a lens barrel includes a first wall section that surrounds at least one access hole, and a second wall section that is other than the first wall section. The first wall section has a first inner circumferential surface and a first distance defined between the first inner circumferential surface and an outer circumferential surface of the at least one lens. The second wall section has a second inner circumferential surface and a second distance defined between the second inner circumferential surface and the outer circumferential surface of the at least one lens. The first distance is larger than the second distance.