A reading device, system, storage medium and method for capturing computer-readable codes of a medical product or packaging. The method includes: capturing an image of the product or packaging, extracting first and second computer-readable code, interpreting code data, retrieving a product-ID and further product information from the code data, determining if relevant information is included in the information of the captured code and/or a linked database, selecting the second code as a relevant code if retrieved information of the first code is fully included in the retrieved information of the second code, or selecting the first and second codes as the relevant code if each code includes relevant information, transmitting a code marker for each code to a displaying device, and displaying an overlay image with the captured image and a marking of the code to provide an improved overview of the computer-readable codes to the user.