Is the idiom in eye of beholder is common idiom?

The phrase "in the eye of the beholder" is a common idiom in English, but it's not an idiom in the strictest sense. It's a proverb, which means it's a short, well-known saying that expresses a general truth or piece of advice.

Here's why:

* Meaning: It means that beauty, truth, or value is subjective and depends on the individual's perception.

* Usage: It's frequently used in discussions about aesthetics, personal opinions, and differing perspectives.

* Origin: While its exact origins are uncertain, it dates back to at least the 18th century.

So, while not a "true" idiom (which typically involves a figurative meaning), "in the eye of the beholder" is a well-established and common proverb, making it a familiar expression in the English language.