A system comprising a stack of layers configured to display an image and including multiple elements configured to sense light. The system is configured to obtain a first reference image based on output from the multiple elements in a dark lighting condition associated with the system, and calibrate object detection based on output from the multiple elements using the obtained reference image. Additionally, a system comprising a display having a stack of layers configured to display an image and including a first and second set of elements. Each of the elements in the first set is configured to sense light, and each of the elements in the second set is configured to sense a dark current. The system is configured to perform object detection based on output from the elements in the first set, and calibrate the object detection based on output from the elements in the second set.