no. not altitude. not medication. not related to blood in your nasal mucus. this is a totally normal optical phenomenon that literally everyone experiences.
Scheerer's phenomenon:
http://en.wikipedia.org/wiki/Blue_field_entoptic_phenomenon
do not use visine for this. no, it will not go away. the more you "pay attention" to it and the more you think about it, the more you will train yourself to see it. its no big deal and there is nothing that can be done to stop it.
Thanks for the response. But why all of a sudden? Both me and my wife started to see this at the same time under the same conditions. We never saw it before, Im always staring in the sky to see my floaters and never saw the white dots.
Also does this explain the dark brown blinking dots I see as well? Or is this a different issue? The white dots move around but the brown dots blink on and off in different locations.
the white dots and brown blinking spots are likely the same phenomenon. you're seeing white blood cells of various types (some larger and some smaller, some more translucent and some less) coursing through your retinal vasculature.
why all of the sudden? dont know. many people notice this phenomenon for the 1st time under the conditions you describe: blue sky, high altitude. harder to see in the city with all of the lights and smog, etc and at lower altitudes, especially low altitudes with high humidity.
once you've "learned" how to see it, you can see it almost any time you look at the sky. it can get hard to ignore.
For something that is "nothing" it sure is bothersome. But I can see it anytime, not just the sky. Even when my eyes are closed. I guess I learned to see it, even when I dont think about it. This is going to be a long life. Bad enough with these floaters.