The Iron Giant (1999)

The head to the Iron Giant bust was clear cast. The eye areas were masked off and the rest of the head painted. After drying the masks were removed thereby preserving the clear eye sockets. Inside the head was inserted a small piece of reflective mylar. Over this were inserted two green LED lights, one for each eye. Coin batteries drive the electronics and are hidden inside the base.

From Wikipedia:

The Iron Giant is a 1999 American animated science fiction film using both traditional animation and computer animation, produced by Warner Bros. Animation, and based on the 1968 novel The Iron Man by Ted Hughes. The film was directed by Brad Bird, scripted by Tim McCanlies, and stars Jennifer Aniston, Harry Connick, Jr., Vin Diesel, Eli Marienthal, Christopher McDonald, and John Mahoney.

The film is about a lonely boy named Hogarth raised by his mother (the widow of an Air Force pilot), who discovers an iron giant who fell from space. With the help of a beatnik named Dean, they have to stop the U.S. military and a federal agent from finding and destroying the Giant. The Iron Giant takes place in October 1957 in the American state of Maine during the height of the Cold War.