Losing sight changes everything, how we move, connect, and experience the world. For people with severe vision loss, hope often feels distant. Blindness is a burden in many societies. Yet, technology is bringing light back in remarkable ways.
The bionic eye, though still developing and not perfect, offers a new chance to see shapes, movement, and even letters. It’s not a full return to normal vision, but for many, even a flicker of light or the ability to recognise faces can mean freedom.
Choosing such a complex surgery takes courage and faith in science, but for those who’ve lived in darkness, even partial sight can open up an entirely new world. You can find the latest findings about the bionic eye in this article.
What a “bionic eye” actually is
A bionic eye (visual prosthesis/retinal implant) is an implanted device that converts visual input into electrical stimulation delivered to remaining retinal neurons (or, in other systems, the optic nerve or visual cortex). The goal is to bypass lost photoreceptors so the brain receives patterns it can learn to interpret as vision.
Fig. 1. Bionic eye: Implanted tiny chip
Who are the candidates?
Best candidates typically have end-stage outer retinal disease (photoreceptors lost) but preserved inner retinal neurons and optic pathways; e.g., advanced retinitis pigmentosa (RP) or some age-related macular degeneration (AMD) patients for subretinal devices. Patients with optic nerve damage are poor candidates for retinal implants. Detailed screening, imaging and electrophysiology are used to select patients.
Practical considerations for retinal implants
Retinal implants are done in specialised centres in different countries. For example, the School of Medicine, Pittsburgh University, USA, Retina Implant AG, Germany, Vision Institute, France, Retina, Australia, Barraquer Foundation, Spain, Moorfields Eye Hospital, UK, etc.
Expect a multidisciplinary pathway
Retina surgeons, low-vision specialists, occupational therapists, and device representatives are typically involved.
Ask about outcomes data
Try to know device-specific clinical trial results for 1-, 3- and 5-year follow-ups, and quality-of-life measures. Let’s see one example here: 5-year results of the Argus II showed long-term safety and benefit for the patients of retinitis pigmentosa.
Main anatomical approaches
The anatomical approaches that are followed for restoring vision are discussed below:
Epiretinal
Epiretinal implants, such as the Argus II, are electronic devices placed on the retinal surface to stimulate ganglion cells. They help restore limited vision in patients with advanced RP through external cameras and microelectrode array systems (Fig. 2).
Study & timing
Argus II has multi-year follow-up data (including a 5-year safety/performance report published in 2016 and follow-ups since); it was an early commercially available epiretinal prosthesis and has the largest long-term dataset among retinal implants.
Measured acuity outcomes
Argus II typically produced very low visual acuteness by standard charts; improvements were shown mainly in light perception, motion detection, object orientation and localisation, and task performance rather than high-resolution reading.
Reported acuteness in trials was usually much poorer than standard vision (often measured as hand-motion to very low logMAR values, though patients performed significantly better with the device ON vs OFF on functional tests.
Functional meaning
Consistent benefits in mobility, object detection, and orientation, useful for navigation and daily tasks, even though high-resolution central vision was not restored. Long-term implant retention and sustained benefit were reported in many patients.
Fig. 2. The Argus II and Orion
PRIMA: Subretinal photovoltaic chip
Chip placed beneath the retina (in the space of the lost photoreceptors), stimulating bipolar/inner retinal cells. PRIMA uses a wireless photovoltaic microchip implanted beneath the retina to convert pulsed infrared light into electrical signals, stimulating remaining neurons.
Study & timing
Large multi-centre clinical trial results were published in October 2025 (NEJM) and summarised in several reports (PRIMA/Science Corp. press and independent coverage). A Stanford Medicine-led clinical trial of a wireless retinal prosthesis for advanced macular degeneration was successful.
Who was studied?
Thirty-eight patients with age-related macular degeneration (AMD) with very poor central vision but retained peripheral vision from 17 centres in five European countries were included in clinical trials.
Measured acuity outcomes
About 80–84% of implanted patients regained the ability to read letters/numbers/words, with an average improvement equivalent to ~25 letters (≈5 ETDRS lines). ETDRS stands for early treatment diabetic retinopathy study
The best individual's reading performance was up to 59 letters. Some participants reached vision approximating 20/42 (with device enhancements such as zoom/contrast).
Functional meaning
These acuity gains translated into reading of large-print text, recognising shapes/letters, and improved central form vision, i.e., meaningful everyday tasks for central-vision loss patients.
Forewarning
Outcomes depend on training, device settings, and patient variability; PRIMA aims at restoring central vision (macular function) rather than full-field normal vision.
Suprachoroidal implants
Suprachoroidal implants are placed between the sclera and choroid to stimulate retinal neurons with minimal surgical risk. Recent trials, such as the Bionic Vision Technologies device, have shown improved light perception and motion detection in patients with late-stage retinitis pigmentosa.
Devices & studies
Second-generation suprachoroidal systems (multi-channel arrays) have completed early clinical studies with recent peer-reviewed reports (2024–2025) showing good surgical safety and measurable functional gains.
Examples include work led by Petoe et al. 2025 and the Bionics Institute.
Measured acuity & function
These implants typically show modest prosthetic acuity but clear improvements in object localisation, motion detection, edge/contrast discrimination, and daily-life tasks.
The studies emphasise safety (with few serious adverse events) and functional improvements that are sustained over months to years. One published suprachoroidal 44-channel study reported measurable gains across participants.
Optic-nerve or cortical implants
The implants can be placed into the eye onto the optic nerve between the eye and the brain (Fig. 3), or directly into the brain. In the healthy retina, the photoreceptor cells convert the light entering the eye into electrical impulses, which then travel along the optic nerve to the brain.
Currently, these devices have shown that otherwise blind patients can sense motion, locate objects, follow a path and recognise large letters. However, if the optic nerve is severely damaged, the optic nerve implant may not be viable. On the other hand, there could be higher infection, inflammation, and other brain-related issues with cortical implants.
Fig. 3. Optic nerve implant
iBIONICS (Canada)
Canadian startup developing the “Diamond Eye” nano/diamond-electrode retinal implant, aiming for higher resolution and different electrode materials. It represents active Canadian R&D in this domain, though broad availability remains future work.
Key device components & how they work
Bionic eyes include a camera, a processor, a transmitter, and an implanted electrode array. The camera captures images, the processor converts them into signals, and electrodes stimulate retinal neurons, creating patterned light perceptions mimicking partial visual restoration.
Camera & glasses
Many systems use a head-mounted camera (on glasses) to capture the scene. The signal is processed (edge detection, contrast enhancement, AI filters), then encoded into stimulation patterns.
External processor/transmitter
Sends wirelessly (or via a transdermal coil) to the implanted receiver.
Implant & electrode array
Converts incoming signals into electrical pulses delivered to retinal neurons. Electrode count, size, and location determine spatial resolution.
Rehabilitation software & training
Patients learn to interpret the new visual percepts (shape, motion, contrast). Rehabilitation is essential to functional gains.
Risks & limitations
Restored vision is not uniform; outcomes vary by device, disease (RP vs AMD), electrode density, neural health, and rehabilitation efforts. Comparing acuities across studies is tricky; different tests (ETDRS letters, grating acuity, functional tasks), different baseline blindness definitions, and small trial sizes mean you should interpret numbers as approximate signals of improvement rather than guarantees.
Training and software matter; modern systems use advanced image processing (AI/zoom/contrast enhancement) and intensive rehab; these significantly affect what patients can do with the implant.
Surgical complications
Infection, retinal detachment, device failure, and erosion of external components.
Cost & access
High expense, often limited to clinical centres/trials.
Patient variability
Some patients adapt very well; others gain minimal function.
FAQs
What is a bionic eye?
A bionic eye is an advanced electronic device designed to help restore vision to people with severe vision loss or blindness by stimulating the visual system.
How does a bionic eye work?
It works by converting visual information captured by a camera into electrical signals, which are then sent to the brain via electrodes implanted in the visual pathway.
Who can benefit from a bionic eye?
People with conditions like retinitis pigmentosa, age-related macular degeneration, or other degenerative eye diseases that cause vision loss can potentially benefit.
What are the main components of a bionic eye?
Key components include a miniature camera, a processing unit, a transmitter, and an electrode array implanted in or near the retina or visual cortex.
Is a bionic eye a complete cure for blindness?
No, it does not restore perfect vision, but it can improve visual perception, such as detecting light, shapes, and movement.
What are some challenges faced in developing bionic eyes?
Challenges include achieving high-resolution vision, biocompatibility, long-term stability of implants, and reducing surgical risks.
Are bionic eyes currently available to the public?
Some types of visual prostheses are available in clinical trials or specialised clinics, but widespread availability is still under development.
How long does a bionic eye device typically last?
The lifespan depends on the device and maintenance, but generally ranges from several years to over a decade with proper care.
What is the future outlook for bionic eye technology?
Researchers are working on improving resolution, reducing invasive procedures, and integrating new technologies like AI to enhance visual capabilities.
Are there any risks associated with bionic eye implantation?
Risks include infection, inflammation, device failure, and surgical complications, similar to other implant surgeries.
Conclusion
PRIMA (subretinal photovoltaic) demonstrated the largest step toward readable central vision in AMD patients in the recent pivotal trial. Epiretinal (Argus II) reliable improvements in light perception, motion, orientation and mobility tasks; but limited central acuity.
Best safety/surgical ease tradeoff emerging. Suprachoroidal implants are less invasive placement with encouraging safety profiles and meaningful functional gains, though acuity remains modest.