I've had this happen before and I think it's sinuses. My head feels real weird, like fuzzy, hard to focus. If I try to focus on something then I feel like I'm going to barf. This morning it was really bad. I was driving DH to work and it was dark and raining. I had to try and focus on the road when another car went by because their headlights were causing a glare from the rain. I felt like crud.