How can I make the page redirect if the zoom level is not 80%?

I have two HTML files: index.html and zoomerror.html.
The site only displays properly at a browser zoom level of 80%. Is there a way that I can use Javascript to detect the zoom level non-stop and redirect the page from index.html to zoomerror.html if the browser zoom level changes from 80% to some other level? I could not think of any code to do that.

I tried to use the window.devicePixelRatio function for this, but it just caused the page to constantly refresh, even though the zoom level was 80%.