The importance of having a standard form for transferring optical data between Computer-Aided-Optical-Design (CAOD) programs and other, mechanical, electronic, architectural, etc. Computer-Aided-Design (CAD) programs is stressed. Emphasis is put on the need to hold all data required for the model of a large-scale project in a standard retrievable form; optical data forms a small but vital part of this. Working in liaison with ISO TC 184/SC4 (the group concerned with “Industrial Automation” and development of STEP, the Product Modelling standard, ISO 10303), ISO TC 172/SC1/WG4, (“Optics and Optical Systems/Fundamental Standards/Electronic Data Exchange”) has made the first steps towards integrating optical data with other product data. The aim is to present all data necessary for the automatic design of optical systems in a unique and unambiguous format so that it can be safely processed by any other design software that conforms to STEP regulations. Since STEP is planned to embrace all manufactured products it is a very complex standard and fitting the optical data into its format is a lengthy procedure. By international collaboration, the Application Protocol, which defines in STEP terms the optical information to be specified, and the recently completed Application Activity Model, a necessary preliminary stage in STEP mapping the manufacturing process, have been produced and are explained here. Current work on the next stage which involves creating an Application Interpreted Model or EXPRESS schema of the AAM is then described.