Testing Visual Functions in Patients with Visual Prostheses

Abstract

A number of different technical devices for restoring vision in blind patients have been proposed to date. They employ different strategies for the acqui- sition of optical information, image processing, and electrical stimulation. Devices with external cameras or with integrated components for light detection have been developed and are designed to stimulate such different sites as the retina, optic nerve, and cortex. First clinical trials for these devices are being planned or already underway. As vision with these artificial vision devices (AVDs) may differ considerably from natural vision and as it may not be possible to predict visual functions provided by such devices on the basis of technical specifications alone, novel test strategies are needed to comprehensively describe visual performance. We propose a battery of tests for standardized well-controlled investigations in these patients that allow for objective assessment of efficacy of these devices. Introduction