I get golden sparkles from time to time. Like you describe, they are not prismatic or light reflections, and they do have dimension. I have noticed, however, that they tend to happen when I have just stood up or sat down. So either it is something along the lines of being related to autostatic hypertension, or perhaps something deeper and less easily explained. Either way I just observe them, they are cool and just there. Sorry I don't have any concrete answer for you.