The watch comprises a case in which a watch movement is housed, this case being provided with a watch glass supporting a liquid zoom lens for visually magnifying, momentarily, one element of the watch movement which is visible through the watch glass. The liquid lens is formed by an elastic membrane and a first part of a reservoir comprising a transparent liquid. It is switchable between a non-magnifying state where the elastic membrane is substantially planar and a magnifying state where this elastic membrane is curved in response to pressure exerted on the transparent liquid. The watch comprises, in addition, an actuator, provided in order to vary the pressure of the transparent liquid by driving into an elastic wall of a second part of the reservoir, and means for controlling the actuator which can, in one variant, be activated by a user.