Billionaire Lerner is ready to dip into his pockets in a bid to bring the glory days back to Villa Park and take the club into the UEFA Champions League.
O'Neill said: "He has big plans and I realise that if I do well I can realise those ambitions here. Some may call his interest quaint but he wants to bring Villa right up.
"He's here for the long haul and he's enthusiastic now and he was when he came here.
"We're improving at a rate of knots and he recognises that, I haven't put any reckless demands on him because I don't want to put the club in financial difficulty and I think he appreciates that.
"But he's hoping to be here on a more permanent basis in the not too distant future.
"This is not a play thing to him - he's as enthusiastic as the day he took over."
O'Neill, who was quiet in the January transfer window, says he is not scared to spend vast amounts of money if it is made available to him.
He added: "If this football club can afford it, I will happily spend money. I would have no qualms about it.
"We are light on numbers - you can't get away from that.
"The teams with big squads have earned the right to rotate but I'm not in that position right now."