The Stomper Scrutinizer: Web Browser w/Visual Simulation 
The Stomper Scrutinizer is a webkit based browser that includes a simulation of human foveal and peripheral vision. By providing a realistic distortion of non-focused page content, the Scrutinizer reveals the perceptability of design features. It is also useful for conducting usability tests, design reviews, and has a number of features (including screenshots) for talking about design.
Andy Edmonds. StomperNet (2007). Resources>Software>Accessibility>Web Design