Personal interest here is directed towards aspheric and progressive addition lenses, in terms of design, manufacture and simulation. Visual Optics and Instrumentation, edited by W N Charman, Macmillan, London. Visual detection and adaptation to optically induced curvature distortion. Low vision aids . Modern technology has made alternative types of magnification device possible, and electronic devices are now much more economic to use.
Development continues of portable television devices for the use by the partially sighted.