Like a radio, the eye is essentially a device for converting photons into electrons, pulses of electromagnetic energy into electrical currents. Geared for visible light rather than radio frequency signals, the eye is a receiving antenna. Yet, in the crucial index of performance, the radio is drastically inferior to the eye. That is the span of visible light, from 400 terahertz to 750 terahertz, red to purple. It is not chiefly the special powers of the retina and other optical faculties.
Radio antennas can collect an even larger span of frequencies.
The difference is mostly behind the receiver. Backing up the eyes is the processing power of some 10 billion neurons and trillions of synapses. Backing up the radio antenna is a lot of fixed- analog hardware. Eyes are smart and aerobatic while the radio is dumb and blind. In Baran's vision, the future of wireless is the replacement of current dumb radios by smart digital radios that resemble eyes.