The meaning of the contacts' base curve is the curve of radian. I can give you a analogy for the easily understanding, the base curve of a bowl vs a dish, the dish's base curve is more strong than the dish's. Only the suitable base curved contacts would bring you comfortable feeling of wearing. The strong base curve will not lock on the eyeballs, it will be easy to slide on the surface of your eyeballs. It will be unfixed with the location of contacts in your eyes; if it goes to the opposite, the contacts will too fasten to lock on the eyeballs, it will lead oxygen lack, and it will hurt your eyes in a long term. So, the over range of the base curse will do harm to your eyes. You must choose a suitable one for your eyes health.