After defining the scope of the paper and discussing the relation of the design of the display of the reading to the design of the instrument as a whole, some of the special characteristics of the human eye and brain which affect seeing power are described.The various factors affecting the presentation of the instrument reading which have to be considered by the designer are dealt with in detail, and reference is made to subjective tests carried out at Cambridge University and elsewhere.A brief display specification for laboratory and industrial instruments is then given with comments and is followed by a description of recent developments in presentation technique. Finally, possible future developments with a view to improving the readability of instruments are outlined.