She showed him the key and saw his eyes dilate.

She looked up at him, and her eyes dilated with anger.

Her eyes dilated with horror at what she had done.

These eyes, however, dilated in the face of brighter light.

Her dark eyes dilated; she remained standing in the same spot.

Brown eyes dilated as he acknowledged several things, among them her gender.

His eyes dilated all the way to black, and they had a dangerous madness in them now.

This hormone makes the heart beat faster and the eyes dilate.

Yet the two watching humans knew by the way the bat's eyes dilated that it still lived.

"I'm not leaving this room," he said, his blue eyes almost fully dilated.