What you're describing has been known since antiquity. What you first describe (an arc-like enlargening area of blurry vision) has been called a scintillating scotoma and artists and patients alike have tried to describe it with interesting results:
It is important to note that this happens in both eyes simultaneously, so that the same part of the visual field is disturbed in both eyes. (If it in monoccular, it is different and more concerning, and should be reported to your doctor immediately.)
The headache that follows is a migraine. For this reason, this has variously been called ocular migraine, opthalmologic migraine, visual migraine, etc.
It is never a bad idea to talk to your doctor at least once about migraines, even if they are infrequent, though a significant number of migraine sufferers don't seek medical care.
What is an ocular migraine?
Patterns of Diagnosis and Acute and Preventive Treatment for Migraine in the United States: Results from the American Migraine Prevalence and Prevention Study