INQUIRY/ PROMPT: Is it possible to make ultra cheap wearables that use light instead of BLE to connect?

ABOUT: Tribe is a pendant that is programmed through flashes of light that come from a corresponding Iphone app. My main contributions to the project were app development and design (native app, Objective C) and hardware (Arduino to ATTiny85 workflow with charlieplexed LEDs, tilt pin and photocell).