The ball of the eye.
A face-to-face meeting.
A person's focus of attention.
A favourite or pet; the apple of someone's eye.
A readership or viewership.
To roll one's eyes.
To gauge, estimate or judge by eye, rather than measuring precisely; to look or glance at.
To scrutinize.
To stare at intently.
The physics of light and vision.
Perception, image, public relations, especially in politics.
The light-related aspects of a device.