Board Thread:Boruto Discussions/@comment-25319479-20160502145551/@comment-3568954-20160506105012

ok as for Boruto having 1 byakugan. if it is indeed a byakugan and he indeed naturally awakened, there could be a reason for it. once kishimoto was asked what would happen if a uchiha and a hyuga were to have a child. would the child have both the byakugan and the sharingan. kishimoto stated that if that occurred the child would A have either the Sharingan or the Byakugan or B 1 sharingan and 1 byakugan

so Boruto might have some other Dojutsu in the other eye. or he could have just had it transplanted. as for the veins not being present that could be design error where the artist forgot to put the veins or it might not be a byakugan or it could be an enhanced byakugan. people with the tenseigan for example have no vein protrusion yet the tenseigan is an evolved Byakugan, maybe The mixture of sage mode and the byakugan results in a byakugan that doesn't require the veins to protrude