Advances and challenges in the development of visual prostheses

Abstract

The past 20 years have witnessed significant advancements in the field of visual prostheses, with developments spanning from early retinal implants to recent cortical approaches. This Perspective looks at some of the remaining challenges to achieve the ambitious clinical goals that these technologies could enable.

Fig 1. Design of visual prostheses.

All approaches generally share a common set of key components. (A) A camera, typically mounted on standard glasses, captures the subject’s visual field. (B) An external processing unit extracts the most relevant features from the environment, converting visual scenes into patterns of electrical stimulation. This unit wirelessly transmits power and data via a radiofrequency (RF) link to the internal implanted system, which decodes the signals, identifies the target electrodes, and generates the final stimulation waveforms. In some designs, the internal system also supports electrophysiological recordings. (C) Finally, a multi-electrode array is implanted at one of several potential sites along the visual pathway, including the retina (1), optic nerve (2), lateral geniculate nucleus (3), or visual cortex (4).