There is no conclusive evidence that this assists readability. 14 Design and layout Layouts should be simple and clear with recognisable patterns for levels of heading, numbering systems, and treatment of specific information. If text is set in columns make sure the space between columns is generous. If space is limited, use a vertical rule. It is helpful to provide 'navigational aids' for the reader such as a contents list for multi-page documents, and rules to separate unrelated sections.
Bullets can assist the structuring of lists.
15 Forms On forms, visually impaired people often need generous space to fill in hand-written details. Their hand-writing tends to be larger than average, and visual impairment, particularly in older people, is often accompanied by other physical problems which make it hard to write neatly. This means they need more widely spaced lines or larger boxes to fill in than those on conventional forms. Designing Instructional Text , 3rd edition, Kogan Page Limited . Drop us a note .