To prevent pains in eyes caused by salt water or chlorine bactericide by water entering the main body of glasses and to prevent pains like the protrusion of eyeballs caused by negative pressure due to expansion of the inside of the main body.

An annular outer-curved tongue 3 is formed around a watertight ring 2 mounted on an attachment part 1a of a main body 1 of water glasses, an annular thin membrane piece 4 is integrally projected inside the root of a top end part 3a of the tongue 3, and the membrane piece 4 is formed elastically in contact with the skin of a face F when in use. Since the membrane piece 4 is elastically in contact with the skin of the face in normal use and water pressure is applied from the outside of the membrane piece 4 in the direction to further press this piece onto the face, water will not enter.