Frederik Ceyssens on Scaling Cortical Implants with ReVision (Bionic Vision spotlight, 2025)

Key interview content (paraphrased excerpts):

• Ceyssens: researcher at KU Leuven (flexible electrodes with neurosurgeon Bart Nuttin, DBS pioneer); co-founded ReVision Implant with Peter Janssen (neuroscientist at KU Leuven, visual system/brain implants).
• ReVision’s device “Occular”: next-generation cortical prosthesis; ultra-flexible, high-density electrode arrays targeted at primary visual cortex, including deep (up to a few cm) insertion; aims for grayscale vision at over 1,000 pixels of resolution.
• Rationale vs retina: the retina has limited space, overlapping axon tracts, mixed cell types, and must be relatively healthy — “the primary visual cortex is very likely a better spot to implant”; performance trumps invasiveness (every completely blind person spoken to said they don’t mind eye or brain, “they just want something that works”).
• Lesson from Orion/ICVP: electrode count still too low; for the same electrode count, brain implant performance was a lot better (Eye and the Chip conference).
• Engineering: >1,000 electrodes via lithography; flexible to minimize scarring; patented insertion method using resorbable coating that temporarily stiffens the implant for surgery; +15 years of lifetime (accelerated aging tests).
• Deeper electrodes (Martin Bak evidence): >5x better resolution; currents tens of microamps vs milliamps for surface stimulation.
• Pathway: long-term pre-clinical monkey data (Janssen lab, KU Leuven: biocompatibility + eye-tracking responses); next acute intra-operative test with Hungarian partners Lucia Wittner and Richard Fiath (TTK, Budapest) during epilepsy resection surgery; longer-term trial planned with Prof. Eduardo Fernandez (Spain, who has implanted Utah arrays in blind volunteers); fully wireless prototype in development.
• Regulatory: launch in Europe and the U.S.; FDA pre-submission planned; success by 2030: restoring at least 3/20 vision and being ready for pivotal trials.