Various embodiments disclosed herein include an optical module. The optical module may include a deformable lens and an actuator configured to be deflectable to cause a change in the shape of the deformable lens to alter light passing through the optical module. In various examples, the optical module may include a stop structure configured to mechanically stop the actuator from deflecting beyond a threshold deflection in at least one direction. In some cases, the stop structure may be used for calibration purposes. Additionally, or alternatively, the stop structure may be configured to define an aperture stop that limits an amount of light that passes through the optical module. Furthermore, in some embodiments, the stop structure may be configured to hide the actuator when the optical module is viewed in plan.