classic migraine. Go get an MRI to be sure it's not something nastier, then ask about the drugs you can take to stop the process as soon as it starts. Migraines can be triggered by all sorts of things, including being really tired.
The symptoms are very typical for both migraine and TIA. I second (third? fourth?) the recommendation to see a neurologist as soon as you can get an appointment. Both conditions can be managed, but if it is TIAs, you need to address it sooner rather than later.
I get weird vision "spells" from time-to-time too. Blurry vision, rainbow-colored round prisms and sometimes "breaks" in my vision. I don't know what causes them, but they seem to happen mostly first thing in the morning and go away within a couple of hours. There is no pain, but it's weird! If it happens on a weekend, I will just rest and that helps, but they seem to happen most often on workdays when I really just have to just deal with it. Luckily there is no pain, so it's annoying and a bit disturbing, but I'm not incapacitated. I haven't gone to a Dr for it, but was thinking maybe was some kind of ocular migraine as well.
ESG-TIA can be a forerunner of a stroke. It doesn't always indicate a coming stroke, but it does indicate that it's time to get to a neurologist ASAP. Many people have TIA's and don't have a stroke, but it's always a bad thing to ignore.