This article is about the quest item. For the item used to make lanterns, see Lantern lens.
The observatory lens is a quest item made and used during the Observatory Quest. During the quest, a lens mould and a piece of molten glass must be given to the professor in the Observatory. The professor will then attempt to craft the lens but be unable to do so. He will then return the mould and glass to the player and request it be crafted. Once made, the lens should be given to the professor so that the telescope can be repaired.