Systems and methods according to one or more embodiments are provided for annealing a chalcogenide lens at an elevated temperature to accelerate release of internal stress within the chalcogenide lens caused during a molding process that formed the chalcogenide lens. In particular, the annealing process includes gradually heating the chalcogenide lens to a dwell temperature, maintaining the chalcogenide lens at the dwell temperature for a predetermined period of time, and gradually cooling the chalcogenide lens from the dwell temperature. The annealing process stabilizes the shape, the effective focal length, and/or the modulation transfer function of the chalcogenide lens. Associated optical assemblies and infrared imaging devices are also described.