Objective: Shared decision-making is challenging for patients with lung cancer, who often struggle to understand clinical information and make informed choices. Patient Decision Aids (PDAs) are effective tools for educating patients about available treatments and reducing decisional regret. To evaluate their feasibility, eye tracking is one possible methodology. Determining the position of the eyes to track a person's gaze direction at a given time and the sequence in which eyes move allows for providing an objective source to understand visual and display-based information processing. In the present study, conducted within the I3LUNG European project, we developed and assessed a digital PDA to make it more suitable for lung cancer patients. Methods: Six experts in lung cancer psychology participated in measuring attentive focus and engagement with the PDA using eye tracking. Results: participants focused more on detailed information about treatment options and survivorship. Visual attention was higher on text than on images. Moreover, understanding of treatment efficacy and symptoms was a key concern. Lastly, psycho-oncologists showed less interest in the contents about "who can attend to a specific cancer treatment" and their related procedure. Specifically, low scores related to fixation and saccade-based metrics were collected. Conclusions: This digital PDA may serve as a valuable tool for facilitating illness information sharing, aiming to promote shared decision-making. The results helped improve the PDA clarity, scientific accuracy, and layout appeal, making it a feasible support for lung cancer patients during their cancer journey.