“Magic Lens filters are a new user interface tool that combine an arbitrarily-shaped region with an operator that changes the view of objects viewed through that region. These tools can be interactively positioned over on-screen applications much as a magnifying glass is moved over a newspaper. They can be used to help the user understand various types of information, from text documents to scientific visualizations. Because these filters are movable and apply to only part of the screen, they have a number of advantages over traditional window-wide viewing modes: they employ an attractive metaphor based on physical lenses, show a modified view in the context of the original view, limit clutter to a small region, allow easy construction of visual macros and provide a uniform paradigm that can be extended across different types of information and applications.”