aurélien berthomé:
And when you concentrate on a kasina object, so with your eyes open, how do you stay focus on your object with all those little flickering lights all around your eyes? Do you have to close your eyes and focus exclusively on the nimitta? I thought that looking directly at the nimitta, if it wasn't stable enough could cause it to faint, and makes you lose your concentration, so I don't really know what to do because they are on the way for me to see my object.
I don't really get what you mean. Kasina meditation is when you stare at a physical object for a while and then close your eyes and focus on the afterimage to get concentrated. The afterimage is not a nimitta. The nimitta then appears as a sign of concentration, no matter how you did it (kasina, anapana, etc). Let the nimitta get as bright, stable and small as possible, then shift your attention to the nimitta and use that as your new object. If you shift to the nimitta before it is stable, the concentration will fade and so will the nimitta.
Do you mean that the nimitta appears where the afterimage is, but is not stable yet, so you can't focus on the afterimage without also focusing on the nimitta, which will fade?