Wireless Body Area Sensor Networks: MAC and Routing Protocols for Patient Monitoring under IEEE 802.15.4 and IEEE 802.15.6 - NASA Thz Biosensing nano (SAI)
"visible light communication (VLC) LED-based lamp to send a message to the human brain using the eye retina as a relay node. In fact, the eye and the brain can be seen as a natural VLC receiver"