Certain fonts make it laggy to type

Hi there,

Is there a way to fix the issue of some certain fonts being extremely laggy when  typing whereas others I don't find no lag? For example, I recently found when I use the helevetica font it gets really laggy typing but when I use minion Pro there's no lag at all.

Please be aware that i'm dyslexic so do try and explain clearly with illustrations/video if possible.