Eyeglass retainer

An eyeglass retainer adapted to be fitted to the temple of eyeglasses and worn behind the wearer's head comprising:

• a pair of elastic tubes, to those which the ends of temples are forcibly inserted, respectively,
• a pair of wire members, the basal portions of those which are connected to the elastic tubes, respectively, and
• a pair of piece members fixed to the tip ends of the wire members, respectively,
• wherein one of the pair of wire members is slidably inserted through the piece member stuck to the tip end of the other wire member under intervention of given frictional force,
• said other wire member is slidably inserted through the piece member stuck to the tip end of said one of the pair of wire members under intervention of given frictional force,
• inside the each of the piece members, a tube made of elastic synthetic resin adapted to be slidably inserted with the wire member under intervention of given frictional force is embedded,
• the wire members and the tubes made of elastic synthetic resin are configured such that tensile force to be generated when the pair of piece members sliding against the wire members are pulled to such direction that they are away from each other at a speed of 100 mm/min. reaches to a range of from 0.2 to 3.5 N (Newton), and
• first hard member is connected to the basal portion of each wire member, and second hard member is stuck to the end of each elastic tube, screw portions for screw-connecting the first and second hard members are respectively formed to both types of hard members, and the elastic tubes adapted to be inserted with the wire members are interchangeable with the other by unscrewing the screw portions.