Life can be a real headache

I have my PT to thank for this lovely piece of cloth!  Yesterday during PT my therapist brought in this piece of fabric.  She told me that she was going to hold this piece of fabric in front of my face and then she wanted me to turn my head from side to side, and while looking at the fabric count the number of black stripes that I could see.   Can I say this not only brought on a headache, but also dizziness and you can guess the other.  Lets say therapy quickly ended on Monday.