AHA ! I found a before & after of Cheri ...
her hair REALLY grows into her eyes. I've thought about letting it grow out but always end up cutting it - look right at her nose and inside corners of her eyes..and excuse the silly tongue shot - That's her dramatic "I'm havin BIG FUN" Drama Face lol -

but you can see how much it opened her eyes to be trimmed up.
I will say this - think hard before you make a decision to cut any face hair - I do my girls cause they're spying in the yard so much - I noticed the hair sticking into their eyes and just wanted a cleaner look to their faces - but ONCE that hair is trimmed - you have to keep up with it or let it grow ALL over again....and if your yorkies hair is long enough where you can smooth it out of the eyes - I'd try
not to cut.