I have had opthalmic migraines for several years now. From what I understand, they're harmless. It's good to go somewhere dark, close your eyes, and wait for the episode to dissipate.
check out the thread titled "Blurred vision caused by anxiety?" by wursty.
It addresses some points you have questions about.
I am having very strange visual disturbances as well. I have noticed that they do get worse when the stress and anxiety level is high. I have been afraid of a tumor or something. Doctors thought maybe occular migraines but it doesn't really fit what's happening. I think I am going to get some brain scans done, but anxiety definitely makes the situation worse. Having blurry vision, colored lights, vision jumping up and down then clearing, plus more. It has been worsening for about a year and a half. How long has your's been gong on? Do you ever get a zooming effect in your vision?