Colin Farrell rarely notices his son's neurogenetic condition anymore and hails the youngster's progress as "phenomenal".
The In Bruges actor's seven-year-old son James, with ex-girlfriend Kim Bordenave, suffers from Angelman syndrome, a rare disorder which can cause seizures as well as frequent bouts of laughter.
Farrell has revealed James' health has drastically improved in recent years and he now rarely suffers seizures.
He tells USA Today, "He's doing phenomenal. Less and less and less do I see his condition. I'm just keenly aware of his personality. He's really cool. He's got an amazing team of people in his life. We have the seizures under control. He helps us in a way to be better people. He's so much fun to be around."
"I just am crazy about him. His health is good."
The Irish star also has a 23-month-old son, Henry, from a relationship with actress Alicja Bachleda-Curus.