A lens assembly includes a first lens and a second lens. The first lens includes a first optically active portion, a first optically inactive portion surrounding the first optically active portion and a first optical axis. The first optically inactive portion includes a first inclined surface relative to the first optical axis. The second lens includes a second optically active portion, a second optically inactive portion and a second optical axis. The second optically inactive portion includes a second inclined surface relative to the second optical axis. The second lens is coupled to the first lens in such a manner that the first inclined surface is in contact with the second inclined surface, and a gap is maintained between the second optically inactive portion of the second lens and the first optically inactive portion of the first lens.