An optical unit comprising an optical sensor; and an optical device comprising: a light-transmitting member that is arranged in a viewing direction of the optical sensor; a cylindrical body at one end of which the light-transmitting member is held; an excitation circuit configured to provide a signal according to a selection from a plurality of vibration modes; and a vibrating body connected to the excitation circuit, wherein, based on a signal from the excitation circuit, the vibration body is configured to vibrate the light-transmitting member by using a piezoelectric element disposed along another end of the cylindrical body, wherein the vibrating body is configured to vibrate the light-transmitting member in a first vibration mode of the plurality of vibration modes in which vibration displacement of the light-transmitting member becomes maximum and a higher-order second vibration mode of the plurality of vibration modes in which the number of nodes is larger than the number of nodes in the first vibration mode, and wherein, in the second vibration mode, a position of a maximum vibration displacement in the second vibration mode is within a region of the light-transmitting member that corresponds to a field of view of the optical sensor, wherein a drive frequency of the second vibration mode is five times or higher a drive frequency in the first vibration mode. an optical sensor; and an optical device comprising: a light-transmitting member that is arranged in a viewing direction of the optical sensor; a cylindrical body at one end of which the light-transmitting member is held; an excitation circuit configured to provide a signal according to a selection from a plurality of vibration modes; and a vibrating body connected to the excitation circuit, wherein, based on a signal from the excitation circuit, the vibration body is configured to vibrate the light-transmitting member by using a piezoelectric element disposed along another end of the cylindrical body, wherein the vibrating body is configured to vibrate the light-transmitting member in a first vibration mode of the plurality of vibration modes in which vibration displacement of the light-transmitting member becomes maximum and a higher-order second vibration mode of the plurality of vibration modes in which the number of nodes is larger than the number of nodes in the first vibration mode, and wherein, in the second vibration mode, a position of a maximum vibration displacement in the second vibration mode is within a region of the light-transmitting member that corresponds to a field of view of the optical sensor, wherein a drive frequency of the second vibration mode is five times or higher a drive frequency in the first vibration mode. a light-transmitting member that is arranged in a viewing direction of the optical sensor; a cylindrical body at one end of which the light-transmitting member is held; an excitation circuit configured to provide a signal according to a selection from a plurality of vibration modes; and a vibrating body connected to the excitation circuit, wherein, based on a signal from the excitation circuit, the vibration body is configured to vibrate the light-transmitting member by using a piezoelectric element disposed along another end of the cylindrical body, wherein the vibrating body is configured to vibrate the light-transmitting member in a first vibration mode of the plurality of vibration modes in which vibration displacement of the light-transmitting member becomes maximum and a higher-order second vibration mode of the plurality of vibration modes in which the number of nodes is larger than the number of nodes in the first vibration mode, and wherein, in the second vibration mode, a position of a maximum vibration displacement in the second vibration mode is within a region of the light-transmitting member that corresponds to a field of view of the optical sensor, wherein a drive frequency of the second vibration mode is five times or higher a drive frequency in the first vibration mode.