Hong Kong action hero Donnie Yen was in Beijing Tuesday to attend a charity event for children suffering from ambylopia, or lazy eye, held by the Radiant Children's Eye Hospital.

During the event, he sang and played kung fu with the patients and was appointed a goodwill ambassador and honorary director of the hospital, which specializes in youth amblyopia treatment.

Though once the face of the Red Cross Society of China, Yen said regretfully that in recent years he hasn't been able to get involved in as much charity work as he'd like to due to his busy work schedule. He promised that he'd devote much of the vacation time he has planned for the rest of the year to charitable projects, especially those concerning children, "who are the future of this country."

As the father of two, Yen also shared his experience in communicating with children.

"Children tend to ask lots of questions, hardly letting you answer one before they start on another," he said.

"We must let them feel that we pay attention and treasure these questions they ask to encourage their enthusiasm in learning about the world."

He also noted that as his two children suffer from myopia problems, he's been acutely aware of the problems of eye health in children and thanked the hospital for making an effort in contributing to this field.

Yen starred in The Lost Bladesman which premiered in April and has earned 160 million yuan ($24.69 million) at the box office so far.

Upcoming Yen-starring blockbuster, Wu Xia, directed by Peter Chan, also hits screens nationwide next month.