I usually wear glasses for reading, but these have been fitted with an extremely useful device. It is a projection system utilizing a small prism that allows me to see a 1/4 VGA screen in front of my eye. I use the display as I would any other "screen", but because I am looking through it, I can take in other visual information at the same time. For instance, if I am assessing a vase for authenticity, I can call up a database of characteristic markings and compare them side by side with the ones I hold in my hand. The other end of the projector terminates in a speaker device that allows me to take in audio. Since my system understands what kind information I am interested in getting at any time, it controls the volume according to my preferences. If, for example, I am at the airport and my flight is announced, my system will automatically raise the volume to the earpiece and alert me to the fact that my base unit has received a signal regarding my flight.