Originally Posted by
chicken
It sounds like you went blind from losing blood pressure, and/or oxygen to your head, which is most noticeable in your eyes. In order to combat it you need to establish if you are either lacking in blood pressure, or nutrients that allow your blood to hold more oxygen.
I'd agree with the Iron thing, it's a fact that most people don't get enough Iron, helps with haemoglobin which holds oxygen. You'll probably find the cure to this in excercise (lack or too much of), if you are vegetarian (so you need to make up for the lack of meat and look for Iron content in other foods, i.e. Spinach) or just general diet causing lack of blood pressure. It could probably also be caused by a sudden growth-spurt, and be just your body keeping up.