The traveler benevolent full of awesomeness and roundness graced humanity with knowledge beyond our wildest dreams catapulting the world into golden the likes of which have never been seen. Human life quadrupledfied (yes that's a word now), death and disease were only scary stories told to children. Technology made amazing advancments.
And yet....when the lights go out and all is dark..... our ghost turn into floating headlights. Seriously though all this advancement and the answer to seeing in the dark is for this awsome piece of sentient tech to turn into a flashlight. No advancements in night vision were made at all we can float turn ourselves into walking artillery materialize armor, weapons and transport ourselves in an out of ships capable of entering and exiting the atmosphere as easily as we can pull out of a drive way. When the light's go out all the tech goes out the window, someone grab a candle. We built a huge walled city that spans for miles can make just about anything out sparkly stuff (glimmer) but don't you dare turn off the lights !
Edit: TLDR-Seriously a flashlight that's it ?