Does it matter which eye you wear your contact in?

Usually yes, for several reasons. If each of your eyes have different prescriptions, you want to put the correct contact in the correct eye to help you vision in both eyes, instead of having the incorrect prescription in both eyes. Also, your eyes and the back of your eyelids generally are different shapes (although subtle differences), potentially causing different kinds of erosion on the contacts. In any event, it is better to always wear the same contact in the same eye.
Usually yes, for several reasons. If each of your eyes have different prescriptions, you want to put the correct contact in the correct eye to help you vision in both eyes, instead of having the incorrect prescription in both eyes. Also, your eyes and the back of your eyelids generally are different shapes (although subtle differences), potentially causing different kinds of erosion on the contacts. In any event, it is better to always wear the same contact in the same eye.