The Master Unique Device Identifier, or M-UDI, is a requirement in the EU for devices which are “highly individualised”. This will apply to contact lenses and spectacles.
Instead of assigning a different UDI-DI for each variation of clinical size, M-UDI will be assigned to devices which share the same “combination of contact lens design parameters”.
A single manufacturer will have multiple combinations of design parameters each needing their own M-UDI. There may also be different brands, models, or types of contact lens with further variation in M-UDI for the same manufacturer.
Different manufacturers will also have their own versions of the relevant device, each of which would be assigned their own M-UDI.
Master UDI cannot replace a Medical Device nomenclature because they serve fundamentally different purposes. In this case the GMDN Term will bring together a range of devices under multiple M-UDIs across many manufacturers.