Guest Editorial

I have chosen ten articles dealing with modern instrumentation of testing, analyzing, and improving human vision. As the reader will see, we have come a long way from Young's optometer which he constructed from "cardpaper." I am always surprised by the rebirth of basic optical concepts and the coupling of these to state -ofthe -art instrumentation. With this in mind, I have tried to arrange the articles in the following manner: instruments which measure visual performance, instruments which measure components of the visual system, and instruments which test and develop visual aids.