A barrel for an electrically-controllable variable focal length lens in a button-battery type housing includes a hollow isolating cylindrical tube with an inner diameter substantially equal to that of the lens housing, with one or bumps extending radially towards the inside of the tube and forming bearing surfaces for the lens periphery in a same radial plane. First metallizations extend on at least one of the bearing surfaces and therefrom into first channels formed in the internal wall of the tube towards at least one end of the tube, and second metallizations, each of which forms a contact area on the internal surface of the tube to bear against the lateral surface of the lens and extends towards at least one end of the cylinder.