A varifocal lens includes a hollow case having first and second sidewalls facing each other, the first and second sidewalls through which a light passes; at least one light transmission membrane partitioning an inner space of the case into at least two liquid chambers, the at least one light transmission membrane through which a light passes; at least two liquids filled in the at least two liquid chambers; at least one first operating hole formed at the first sidewall; a first actuator disposed to cover the at least one first operating hole and to pressurize the liquid contacting the first sidewall; and a controller configured to control the first actuator to change a focal distance of an optical lens consisting of the first and second sidewalls, the at least two liquids, and the at least one light transmission membrane of the case.