Western imperialism is an obvious factor in the East Asian countries this is popular in, such as South Korea and Taiwan. There's no concrete proof this is a result of imperialism, but the differences between the counterparts North Korea and China provide limited evidence it's the cause.
As for common, the estimates I can find show between 1/5th and 1/3rd of South Korean woman receive double eyelid surgery.
As for common, the estimates I can find show between 1/5th and 1/3rd of South Korean woman receive double eyelid surgery.