If there were clear evidence that the gouging was intentional, then it seems to me a lifetime ban would be in order. It ought not to depend on the extent of the injury it caused: it should be evident to all persons past the age of reason that there is a high probability of grave injury in eye-gouging, regardless of the outcome. In many jurisdictions, intentional gouging could also be subject to legal sanction. Intentional gouging is far, far outside the range of risks to which we assent in playing rugby.
However, for a lifetime ban to be justified, there would have to be clear evidence (or an admission) that the act was intentional. It is very easy for incidental contact to the face to occur, even incidental contact that leads to grave injury. Before we brand someone for life as guilty of grievous bodily harm, the level of proof should be exceptionally high.
It certainly ought not take the blinding of a major international star to cause action. Not only because we do not wish major stars to be hurt, but because it is not the fame or skill that is the issue - it is the lifetime damage to another human being as a result off an intentional act. Could be a third-side prop for a pub-league team.
Mark L.