Prosthetic vision assessment

As visual prostheses continue to evolve, assessing their efficacy assumes paramount importance. This chapter identifies some of the key questions and issues that arise when planning and designing such assessments, in order to help point the way forward. High quality evaluations will naturally follow basic scientific principles such as including pre-operative as well as post-operative testing. Evaluations should include both visual function and visual task performance. Improved visual function tests may need to be developed or adapted that are suitable for the levels of vision afforded by current and near-term prosthetics. In assessing task performance, the choice of tasks to be assessed is critical, and can greatly influence the results. Longer-term follow-up testing after periods of acclimatization and training are also necessary, with control groups receiving alternative training such as more conventional rehabilitation or interventions. Self-assessment of difficulty in performing daily living tasks is also important, as are the more subjective assessments of user satisfaction. As the technologies continue to evolve, there will be a changing dynamic involving the steadily improving capabilities of the technology and the unique needs of a growing number and more diverse target population.