To mages, Mystic Eyes were something to covet.
{Seeing} was the first magecraft in human history.
Strictly speaking, there was no hierarchy among the five senses.
For humans, at least, they were all indispensable, but undeniably, sight handled the largest share of processing and gathering information.
For that very reason, in most regions, mysterious or incomprehensible natural phenomena were interpreted as eyes.
The sun and moon were often regarded as the eyes of heaven, with the Eye of Horus in Egyptian mythology being a clear example.
And beyond those distant examples, natural phenomena humans happened to notice, such as the eye of a storm, influenced mythology in turn, giving many wind-related deities a one-eyed image, such as Odin in Norse mythology.
The same applied to volcanic craters. Glowing red in the night, they were often regarded as the eyes of the earth, lending the goddesses associated with them a demonic, savage aspect as well. The connection between Medusa and Gorgon in Greek mythology came from this.
The sky, storms, and earth were all nature's Mystic Eyes, constantly watching humanity and turning their gaze upon sinners to deliver punishment when necessary.
In Chinese culture, appeals for Heaven to open its eyes when seeking justice or praying were born against this backdrop.
Even in modern times, this influence endured. The Freemasonry symbol that frequently appeared in conspiracy theories was an adaptation of the all-seeing eye of the Cross Church's Trinity, while black holes were also known as the eyes of the universe.
For this very reason, although Mystic Eyes were an innate talent like Magic Circuits, they were far rarer than mages, since they were semi-independent organs in themselves, or even the materialization of a particular phenomenon and privilege.
Given this theory and reality, along with their single-action activation, ease of use,