I printed a Braq for a work colleague some time ago and wanted to add LED eyes but not to the extent I had done before. Few prototypes later I settled on something that worked well for my goal and figure others may want to do the same.
They take standard 5mm LEDs and you'll need to figure how you want to power it. I used a USB cable so it could be powered easily by and USB charger, computer jack or battery pack.
If I ever have to do another I may repurpose the guts of a solar outdoor walkway light.
I used Ninjaflex Semi-Flex Snow. You will want to use a flexible filament or perhaps soften a PLA with a heat gun to seat it.