A good book which covers this is called "The Divinization of the Christian", According to the Greek Fathers, by Jules Gross.
I'll give you a few small excerpts from the book, typing the whole thing out would be too much.
pg 61-62 "Beggining with St, Ireneous, many fathers concluded from the account of the forming of Adam that a certain deification of the latter exists. Distinguishing between image (eikon) and likeness (omoiosis), they understood this latter item in the sense of a more perfect similarity, which would surpass by far what humankind possess in their nature.
In reality the sacred writer (Irenous) employs the two terms like synonyms, perhaps with the slight difference that the second should clarify the first.........
pg. 221 "Consequently Cyril (of alexandria) distinguishes a twofold divine likeness in Adam: The one given with his reasoning and free nature; the other due to the prescense of the Holy Spirit in him. The latter is far superior to the former because it makes mankind partkae of incorruptibility, which is an essential property of the divine nature.
Basically therefore Cyril takes up again the distinction of Irenious, but with the difference that he vigoriously affirms the perfect synonymy of the biblical terms eikon and omoiosos........"
The book analyzes a few other fathers on their distinction between the terms. For me after reading the quotes from the Fathers supplied by the book its more for the sake of exegesis rather than doctrine between the two terms