Diseases such as macular degeneration can damage the light-sensitive cells on the surface of the eye’s retina. Eventually, the patient can lose sight altogether. Researchers have been investigating ways to create implants that would convert light into electrical signals that could stimulate the optic nerves, restoring vision. (See “Retina Implant Allows the Blind to See.”) A paper published in Nano Letters describes a novel approach developed by researchers in Israel using carbon nano-tubes (CNT).
The process involves adding nanorods to a CNT matrix. The quantum rods convert light energy into electricity, which is conducted by the CNT to the neurons. Unlike solutions using silicon chips, this approach creates a thin and flexible layer that does not require external power to operate.
The scientists have already tested the technology on baby chicks before their retinas are developed, and have demonstrated that the signals can be transferred to the brain. The team is now testing the material for long-term use in living subjects, and is working with a surgeon to develop procedures that could be used for human trials in the future. If this process works, it could restore sight for many of those with limited or no vision at all.