This application is the U.S. national phase of International Application No. PCT/GB2019/050180 filed Jan. 23, 2019 which designated the U.S. and claims priority to GB Patent Application No. 1801320.1 filed Jan. 26, 2018, the entire contents of each of which are hereby incorporated by reference.

The present technique relates to the field of visual implants.

Blindness is a sensory loss with major negative impact on the individual's quality of life. An estimated 39 million people are affected worldwide, with numbers likely to increase given the demographic ageing and the increasing incidence of diabetes-related conditions. Potential treatment options include direct electrical stimulation of healthy parts of the visual pathway. Retinal stimulation can elicit useful visual sensation in patients with retinitis pigmentosa, however loss of ganglion cells precludes this approach. The optic nerve, lateralgeniculatenucleus and visual cortex represent feasible stimulation targets.

At least some examples provide a visual implant comprising:an array of micro-electrodes including at least two stimulation micro-electrodes each comprising:a core of conducting material;insulating material surrounding the core; anda layer of metal or metal oxide nano-structures deposited on tips of the micro-electrodes at a front end for interfacing with a target site for visual stimulation; andan integrated circuit to control a pattern of stimulation current driven through the array of micro-electrodes.

