The blind's sanitary cup / universal cup

This is a sanitary cup for blind people. There are many problems when a blind man is pouring away the water to a sanitary. The blind do not know when the cup is full of water. Blind people need a special sanitary used in public. The blind’s sanitary cup skillfully solves the problem. Near the mouth of the area is thinner than other local cups, because of the pressure, when the water over flows the ring of the thinner concaved area originally will come out. The blind man is through the convex feel of the water in the cup is full.