Low-power through-body communications for smart contact lenses

Smart contact lenses require low-power inter-eye communication to support binocular sensing without a shared electrical ground. This paper presents a ground-isolated galvanic body-coupled telemetry link between independently powered ocular platforms. A reciprocal two-port channel model predicted approximately 50 dB inter-eye attenuation, validated through human-head and ex vivo pig-eye transfer-function measurements. Communication experiments with off-the-shelf chips achieved packet success rates of up to 99.61% through biological tissue. Energy analysis showed that the straight-serial transmitter consumed approximately 208 μJ/message (5.5 μJ/bit) at 9.6 kb/s, while the biphasic signaling scheme reduced the transmitter energy to 14.9 μJ/message (0.391 μJ/bit). These results demonstrate the feasibility of low-power galvanic body-coupled inter-eye communication for future smart contact lens systems supporting binocular sensing, differential magnetometry, and ocular telemetry.