This is the 3rd incident of having a sudden onset of inability to focus. Each time I was sitting down and at a computer terminal. The 3rd time (today) I felt a rush in my head, then the eyes would not focus. Eyesight was swimmy , unfocused. I had my co-worker look at my eyes. She said my pupils were very small, then came back to normal as my vision cleared. I ve been headachy all day... not a blinding headache, just pressure. I m a 65 year old female otherwise healthy (take low dose of thyroid medication).