We propose the Navisio software as a new integrated system to help low vision patients read complex electronic documents (here, PDF files) with more comfort. Navisio aims at taking into account main psychophysical results on reading performance of visually impaired patients. To do this, we analyze what are the main factors in uencing reading performance, and review some existing reading aid systems, dealing with printed and electronic documents. Then, we show how Navisio allows to extend the capabilities of existing reading systems, focusing on the facilitation to navigate in complex documents, and on the highly customizable display. Navisio performance was evaluated against a standard CCTV magnifier tool, with 26 low vision patients. Two kinds of texts were proposed (simple and complex documents) elaborated from a standardised text database. Results show a clear advantage of Navisio in terms of reading speed and comfort. Navisio is intended to evolve: we discuss how it could be extended to any scanned document, thanks to recent computer vision approaches in document layout analysis. Further challenging perspectives are also mentioned.