Print for Partial Sight

Differences Between Adults And Children

Changes in typography affect adult readers much more than children (although print requirements for younger or partially sighted children might be more critical). Adults will almost always be less tolerant of the unexpected.

Type Size

Size of type is one of the most important typographic factors for partially sighted readers, but this is not to say that books in extra-large print are required for all partially sighted readers, or that legibility continues to increase with successive enlargement.

There is a basic difference between adults and children in this respect. The adult often needs larger than average print, but the child, because he/she still retains powers of accommodation, can achieve adequate enlargement by bringing the print close to his/her eyes.

Enlargement much beyond the size that is necessary for the type to be seen is unlikely to increase legibility.

Type Weight

Increased weight or boldness of type, although of secondary importance compared with size, also improves legibility for partially sighted readers. Results with children suggest that once above the lower threshold of vision, weight becomes a more important factor than size.

Typeface

The effect of differences between the typefaces tested (a serif and a sans serif) is of minor importance compared with the effect of size and weight. The sans-serif face was slightly more legible for the adult readers, but no measurable differences between the faces were observed with the children. The sans serif used was Gill Sans, the serifed face was Jenson. The slight preference recorded by adults for the serifed face could be explained simply by the fact that most of their reading will have been of serifed faces.

Type Spacing

Changes in spacing either between letters and words, or between the words only, or between the lines only, do not appear to affect legibility. These rather extraordinary conclusions are contrary to all other surveys on readability of texts.

Cause Of Partial Sight

Legibility varies with typographic changes according to the pathological cause of partial sight. However, there is no real conflict of interests here as typography that is helpful for one group is not positively bad for one of the other groups.

Amount Of Residual Vision

There is no direct correlation between the amount of vision remaining in a defective eye and the use a person makes of it in reading. The personal attributes of the reader—willpower, incentive, and interest in reading—play as important a role as the physical amount of vision in determining whether a partially sighted person actually does much reading.

Importance Of Typography

Although many other factors also affect a partially sighted person’s ability to read print easily, the part played by typography is significant, particularly for adults: the increase in legibility due to improvements in typography measured in this investigation were of the order of 35% for adult readers.