thanks for the questions, I will try to explain my idea.
The screen which I am talking about is not a screen connected to my presentation computer but the one connected to the (eye-tracker ) data acquisition computer. I can use iohub to get gaze positions from that computer, and I can send triggers to store together with eye-tracking data, however, I was wandering how (or rather if) I can send the screen that subjects see to data acquisition machine and display during data acquisition (now I only see gray screen and subject’s gaze during recording on the data acquisition computer). I know that there is (must be) a way to do it using Eye-link experiment builder software.
PS, the second option could be to create a second window (on a second monitor) on my presentation computer, duplicate whatever they see there and a gaze cursor. For the time being I am favoring the first way (if it is possible to do it this way) .