A sight. A saddle is connected between an ocular housing and an objective housing. A crosshair is disposed in the ocular housing. A light-emitting element is disposed in the ocular housing, illuminating the crosshair. A focal adjustment member is disposed on the saddle, adjusting an objective focus for the sight. A key-type member is connected to the focal adjustment member and is electrically connected to the light-emitting element, controlling operation of the light-emitting element and adjusting luminous brightness thereof.