Board Thread:Theories and Speculation/@comment-26773508-20150908113839/@comment-5407586-20150908121748

I say that Shin Sr. cloned "his" right eye and implanted the new eyes in his clones and all over his body. Or, maybe, since his clones were created from his teeth and nerves, there's the chance the Sharingan became a part of the clones' genes and "naturally" manifested. Meaning that, were the clones to have offsprings, said offsprings would awaken their own Sharingan as well.