Any idea what these spots or shooting stars are in front of my eyes?!

Any idea what these spots or shooting stars are in front of my eyes?

If i've just had a shower and i dry my hair vigourously or cough a lot i get these little shooting star type things in front of my eyes for about 10 seconds afterwards. Any ideas?

I have been told that it is most likely from blood pressure changes when that happens. I am a vertigo sufferer and I also get dizzy easy. This happens to me and I thought it was part of that, but both my regular doctor and the Optometrist I work for said it was most likely blood pressure changes that happen when you tilt your body down and stand up again really fast. You see it in your retina when the blood changes in the capillaries and blood vessels there.