If you have a stroke do you suddenly get a blind spot?

Not necessarily: Not necessarily. A stroke involves a loss of blood supply to an area of the brain. The specific type of defect depends on which area of the brain is affected, symptoms can range from visual defects, loss or speech difficulty, difficulty walking or using extremities and so on. The size (and to some extent the symptoms) depends to to a degree on the size or caliber of the artery involved.

Depends: It depends on where the stroke occurs. If it occurs in your eye, then yes, but it also depend on where in they eye. If its the brain, then it depends on where in the brain.