I've suffered from chronic hemiplegic migraines my entire life, (the bane of my existence) ... visual disturbences are normal, and I've actually gone blind twice, and have tunnel vision and light flashes normally.
The biggest problem with my particularly rare form of migraine is that they stay in the vasoconstrictive stage, (which is what causes the hemiplegia), so I can't take any SSRI's or other types of vasoconstrictors, only opiate pain medications, which come with their own set of problems.
Hang in there and see a good neurologist ... they can be managed with many prophylactic medications, such as beta blockers, calcium channel blockers, antidepresants, etc. Hope it gets better for you ... it's a level and type of pain that is unlike most others.