We see at the end of "Oxygen" that
the doctor loses his eyesight.
Couldn't he have just used regeneration energy to heal himself? He had done so on other occasions, to heal others (River for example). Also in the last episode (Lie of the Land) he
uses regeneration energy for no real reason (as he could just say to Bill this was all a trick after she shot him).
So, is this just an inconsistency?
edit: The question here does not focus on the use of regeneration energy, but generally on anything that could
heal the Doctor's eyesight, because he said there exist such things back in the TARDIS
The answer to the question was given before the last episode aired, so the part of the argument about the Doctor possibly not having "enough" energy to heal we know is not true (as the use of the energy for Bill to see is rather pointless, as Mr Lister said in the comments). In addition we know that he can use regeneration to heal himself as the 10th Doctor had done in Journey's End.
(The more I think of this, the more I believe it's just something they did not really think through)