The shortcomings of the standard glass 'maps’ that currently appear in optical design programs are discussed. There is a clear benefit in having a glass map that is interactive, i.e. allows the user to change system glasses directly from the map. This has been implemented in the WinLens software, and the work is reviewed in this paper. Most aspects of this 'active’ map can be customized to suit the requirements for any given lens design task. Standard maps, such as n-v-diagrams, may be generated, but for non-standard wavebands. Unusual variable combinations, such as internal transmission versus dispersion, may also be displayed. Finally, glasses in these plots may be color coded to display one or more extra optical, chemical, mechanical or thermal properties. These simple new tools can reveal significant correlations between properties and allow the designer to effectively consider a wider range of properties in his glass selection.