To focus the Oculory you need to equip your flames and frostbite spells.
Once you get to the Oculory place the focus crystal in it. Make your way through the dungeon, it may take a while(did me). Which are fairly strong so take plenty of potions with you. This dungeon contains Falmers, Chaurus' and Dwarven Automatons. *possible spoilers* i will try to keep them to a minimum. Complete the 'Revealing the Unseen' quest, which is the fifth quest in the College of Winterhold quest line.
