Marc Wolf's doctoral thesis describes a way to employ visual evoked potentials for a fully objective acuity evaluation. My role was creating some of the analysis tools and providing mostly technical advice.
For more information, visit this page, or take a look at the following publications.
Wolf ME, Maurer JP, Bach M (2005) Objective Estimation of Visual Acuity — High Correlation Across Normal and Diseased Vision with an Automated VEP-Based Algorithm. Proceedings of the 8th Tübinger Perception Conference, p. 110