This is because many people with partial sight have difficulty finding the beginning of the next line while reading. Not effective leading 5. Font Family Avoid complicated, decorative or cursive fonts and, when they must be used, reserve them for emphasis only. Standard serif or sans-serif fonts, with familiar, easily recognizable characters are best. Also, there is some evidence that sans-serif fonts are more legible when character size is small relative to the reader's visual acuity.
Roman typefaces are effective.
Decorative typefaces are not as effective. Sans-serif typefaces are effective. Condensed typefaces are not as effective. While there is little reliable information on the comparative legibility of typefaces, there is some evidence that a roman typeface, using upper and lower cases, is more readable than italics, oblique or condensed. Upper and lowercase type is effective.