What is the origin of the idiom "look a sight" and when to use it?

The idiom "look a sight" originated as a colloquial expression to describe something or someone that is visually unattractive, unusual, or comical in appearance. It emphasizes the idea of the subject being visually striking or attention-grabbing in a noticeable way. The idiom is often used to describe situations where the appearance of someone or something is notably different from what is considered typical or expected.