R2-D2 (Hoth)

A reliable and versatile astromech droid, R2-D2 has served Padmé Amidala, Anakin Skywalker, and Luke Skywalker in turn, showing great bravery in rescuing his masters and their friends from many perils. A skilled starship mechanic and fighter pilot’s assistant, he has an unlikely but enduring friendship with the fussy protocol droid C-3PO.

from – R2-D2 | StarWars.com

Even though the effect is very subtle, I added a red SMD LED to R2-D2’s interior. R2’s red eye is a 0.5mm thick glass fiber, which lets the light of the LED shine outwards.