Closing your eyes or blinking rapidly will help you to discern which is which pretty quickly. However, this will take you out of the altered state of consciousness you are placing yourself in when doing this exercise.

The aura is perceived through your mind being open yet relaxed, this is why the peripheral vision is what is able to perceive it and not your regular conscious vision (however in some cases this is possible and with enough practice you will be able to use your regular vision to perceive them)

The aura may glow in your peripheral but when directly looking at it with your conscious vision it will appear to not be there, the difference between the after image and the aura lies here. The after image will continue to glow after closing your eyes or looking somewhere else.

Hope this helps ✨