If its not vascular or neurological or retina and nothing changes then I wouldn't worry about it. If something changes then she needs a reevaluation. Sometimes isolated vitreous traction not enough to cause a tear can cause those symptoms.
JCH MD
I was searching for something else and came across that other post you referred to. I guess I can't reply to it, so I came here.
I just wanted to say that I have insulin resistance and take Metformin for it. Before I started the medication I had flashes all the time. I can't say they were colorful. More of a bunch of spots of light that would flash and then fade away. I've been taking Metformin for about 3 years now and since I started it I haven't had a migraine and the only time I've had the flashes has been when I've failed to take the medicine for 2-3 days. So, I'm confident it is sugar related for me. Just wanted to throw that out there just as something else to look at.