1. An unmanned aerial vehicle comprising: a housing; a motor carried by the housing, the motor being configured to drive a rotor; a first optical element configured to guide light to a first image sensor, the first optical element having a first field of view; the first image sensor configured to generate a first output signal conveying first visual information based on the light guided to the first image sensor by the first optical element, the first visual information including an object while the object is within the first field of view; a second optical element configured to guide light to a second image sensor, the second optical element having a second field of view; the second image sensor configured to generate a second output signal conveying second visual information based on the light guided to the second image sensor by the second optical element, the second visual information including the object while the object is within the second field of view; wherein the first optical element, the second optical element, the first image sensor and the second image sensor are attached to the housing; further wherein the first optical element and the second optical element are arranged to be separated by a horizontal distance when the unmanned aerial vehicle operates leveled with respect to ground; and further wherein the first optical element and the second optical element are arranged to be separated by a vertical distance when the unmanned aerial vehicle operates leveled with respect to ground such that the second optical element is above the first optical element; and a processor attached to the housing, wherein the processor is configured by machine-readable instructions to: provide flight control for the unmanned aerial vehicle; receive the first output signal and the second output signal; and compare the first visual information with the second visual information to determine a disparity of the object.