This doesn't happen all the time and there doesn't seem to be anything particular that triggers it.when it does happen, I have to completely stop what I'm doing because I cannot see and stagger when I try to walk. I have no known health problems.

What does your doctor say?

I haven't seen a doctor about it thinking it was diet or etc. the tongue numbness has happened only twice( recently).

Um, if it were happening to me, I'd pay a visit to my doctor.

If you can't SEE? And you STAGGER? And your tongue is NUMB? Definitely get it checked out.

I guess you are right. I have ignored it for a while thinking it wasn't important but since this numbness started too, I'm a bit worried. Thank you!

If it turns out to be nothing, you can feel good about going to a professional and getting an answer. If it's something serious, you can feel good about tackling the problem while it's still fixable. In any event, please report back. I want to know what it is (or that it's nothing). I really do care!

You NEED to get your blood pressure checked ASAP.

These are symptoms of extremely high blood pressure and can result in either stroke or seizures.

Of course it can be nothing, but I would not ignore it. It almost sounds like signs of mini-strokes.
Your doctor will probably (hopefully) rec a neurologist.. but please, don't ignore these signs..