|— Snotlout and Heather argue about the lens on Heather's belt|
|“||My father gave this to me when I was little. I just thought it was... Well, I don't know what I thought. [src]||”|
|— Heather, about her lens|
Heather was given the mysterious lens by her father Oswald the Agreeable when she was a small child. She never knew what it was or what it was for, but she wore it on her belt in memory of her father.
|— Hiccup and Astrid had not noticed the lens that was on Heather's belt|
In "Sins of the Past", the Dragon Hunters have possession of the Dragon Eye, and as their new leader, Krogan is determined to get a hold of the lens that Heather wears on her belt. He manages to get her to trade it for her dragon Windshear. Turns out, the Riders had never noticed it on her belt even after so much time they spent together, neither did Heather realize what it was after watching the Riders work with the Dragon Eye and the other lenses during that time. Now everyone is curious about what info it contained, but it's in Krogan and Viggo's hands. It is uncertain how exactly Krogan knew Heather had it to begin with, though it is suggested Johann was the only one to ever notice it and then passed that info onto Krogan and the Hunters, hoping it will lead them to the "King of Dragons."
|“||And, you know, also that we never noticed Heather had a Dragon Eye lens smack-dab in the middle of her belt! [src]||”|
- Oswald gave both Heather and Dagur a Dragon Eye Lens, unbeknownst to what they were, until "Sins of the Past" and "In Plain Sight" respectively.
- Both of these lenses lead to the same place: Berserker Island, which is their home and the location of the King of Dragons.