In one aspect, a system for controlling the focus of a lens is disclosed. The system may generally include a sensor configured to detect changes in a focal distance of the lens and a thermal device configured to adjust a lens temperature of the lens. In addition, the system may include one or more computing devices communicatively coupled to the sensor and the thermal device. The computing device(s) may be configured to control the thermal device such that the lens temperature is adjusted in a manner that reduces variations in the focal distance.