I get blurry vision in my right eye and then half hour later I get a migrane headache. What might that be?

Migraine with Aura. The blurry vision is probably an "aura." this is not unusual before onset of a classic migraine. Experienced migraneurs often take preemptive treatment during an aura in order to stop migraines before they become severe. If you haven't yet been evaluated by a doctor please do so... Although migraines are relatively benign, other more serious conditions could cause similar symptoms.
Aura. Many times due to a vacular instability patients will feel like they have colored lights in their vision or parts of their visual field which become blurry or grey. This usually affects both eyes. I would still see an ophthalmologist because it is only affecting one eye which is a little atypical for an aura.