fickle; changeable; ever-changing
Idiomatic expression comparing something to a cat's eye, which changes shape with light. Used for things that shift frequently and unpredictably, such as plans, moods, or situations.
His feelings are as changeable as a cat's eye.
The weather forecast is fickle and unreliable.
Literally 'cat's eye'. The expression comes from the way a cat's pupil changes shape dramatically depending on light conditions, symbolizing something that is constantly shifting and unpredictable.