The Dao eye fundamentally only existed in legends. It was said that the Dao eye could see through any illusion and deception, as well as any items that were of a lower caliber than the Dao eye law. This was an eye that could see the Heaven Earth Laws very distinctively.
All things in the universe were considered a type of law. In other words, a Dao eye that attained a sufficient level could see through everything in the universe.
A cultivator unskilled in the Array Dao could see through the array formation to spot the location of the array foundation if the Dao eye reached a certain level.
Di Jiu looked at the Nomological Eye he was holding in excitement. He had obtained many valuable items before, but he knew that the worth of the Dao eye to him now was second to only the Ninth Dao Law.