Normal or paranormal

This may be a weird thing to ask here, but I've been a little worried. I've always seen "weird" things, like a white "line" around people, "streams" in the air, so I can never tell from inside whether it's raining when looking out of a window. I was on a plane and staring out of the window, I started seeing these black spots moving like a kaleidoscope, then they turned into what looked like a flock of birds flying, then they turned into what looked like people half under water, struggling to swim. Since the plane was above the ocean it freaked me out a little. Nothing happened, obviously, but I'm starting to get a little scared of these black spots. So my question is: is it normal to start seeing white or black spots which might transform into crazy things after staring at something for longer than like 5 seconds? Does anyone know what it could be or mean?