Feelable cup / Cup for blind people

People, visually impaired, face embarrassing and difficult situations every time when they try to drink water. For instance, it is difficult for them to estimate how much water is in a cup, when pouring water into the cup, and how much water is left in the cup, when holding the cup on a table. '-' solves the problem with the principle of water pressure. Grooves are cut on the cup several times and tube membrane is put on grooves to block them to make tube bulge with water pressure. Users can know the amount of water in the cup easily by holding the cup.