I'm modifying a model and trying to add simple expressions like blinking and etc.

I'm trying to mirror a closed eye to the other side, but it causes the whole model to become symmetrical, I can't figure out how I can only mirror selected parts :|

Here's an example: https://www.youtube.com/watch?v=Qd4rqPp6hW0&feature=youtu.be

You can see his forehead and parts of his cheeks are getting symmetrical

Thanks in advance!

I'm modifying a model and trying to add simple expressions like blinking and etc.

I'm trying to mirror a closed eye to the other side, but it causes the whole model to become symmetrical, I can't figure out how I can only mirror selected parts :|

Here's an example: https://www.youtube.com/watch?v=Qd4rqPp6hW0&feature=youtu.be

You can see his head shape and and parts of his cheeks are getting symmetrical

edit: another example, the difference between the basis shape-key and the mirrored one: https://gfycat.com/ThirdHealthyGalapagosdove

Thanks in advance!