Since humanity's origins that the eyes are fascination objects by the Man. There are archaeological discoveries that prove that Caldeus, Babilons, let registrations in stones on the iris and its relation with the remaining of the body. In the antique Egypt were found ceramic where were painted inclusive eyes with iridologics signals.
In Greece Antique, Hypocrites, father of the Medicine, also had interest by the study of the iris with the diagnosis purpose. As there are references in registrations of the Scale of Salerno.

In 1670 D.C., Phillippus Meyens, Dresden, in its work Chiromatic Medical, mention the signal in the iris and which ones are main, as well as gives a basic understanding for the first map of the published iris.
Already in 1695, in Nuremberg, Joahann Eltholtz, it wrote scientific jobs about signals in the iris.

Cristian Haertels, after 91 years, in Goettinger, elaborated a fundamental work in Meyens' Studies and Eltholtz, called De óculo et signo (the eye and its signals), which caused much polemic at that time

Here you meet various interesting books and links.