The Light That Blinds Quest Guide
There are two parts of this quest worth mentioning here in this guide. The first part is finding The Deep One's Sinew that you need for an early tier of this quest. The Deep Ones that you need actually aren't called Deep Ones. They are called Talba Bay Creature, as seen in the picture and video below.
The second part of this quest worth mentioning is when you must combine them. Everyone is expecting an easy right-click from your inventory but what you need to do instead is hit (Y) to bring up your Assembly window. Once you've brought up the window you can combine everything together.