Devices and methods for optical-based tamper detection using variable light characteristics are disclosed. In one embodiment, an electronic device may include a housing, a light source within the housing configured to emit light having an output light characteristic that is variable, a light detector within the housing configured to receive the light emitted by the light source, the light received by the light detector having a received light characteristic, and an optoelectric controller in communication with the light source and the light detector, wherein the optoelectric controller controls the output light characteristic, and compares the received light characteristic to a known received light characteristic.