In some cases, the eyes will once again drift apart years after surgery. The surgery doesn't correct the original defect that caused the brain to let the eyes wander in the first place, so the problem might come back years later. But it doesn't always come back. In fact, most patients require just one corrective surgery over a lifetime. If it does come back, it's usually possible for a skilled specialist to again reposition the muscles and restore the benefits of straight eyes for the patient.