Help me with a name for this symptom

I experience this a couple times a week, and I am struggling with how to explain it to the people around me.

I feel lightheaded, but I don't have any problems with my balance. Like my eyes can't focus, but that's not the case, it just feels that way. It's like my brain is slow and processing visual information slower than usual. I also get clumsy and will sometimes walk into things when this happens.

I hope some of you know what I mean. What is the name of this symptom?