strange vision effects.?
so heres whats going on if im like in class taking notes and lets say my book is next to my notebook and its like purple then i look up and see like a shadow of where that book was even if i wasnt looking down for more then a few seconds. it keeps happening when i look at color things and look away i can still see like the outline.. kinda like when you look at the sun and look away .. why is this happening should i be concerned