He suggested that a preoccupation with the arrangement of blocks of text led to the reduction of words to mere colour and a denial of their meaning.…In a series of objections to the cult of sanserif, he asserted that it was not the duty of letterforms to correspond to the spirit of the age, nor to its newest material products (skyscrapers or car bodies); rather “typography must be itself. It must be adapted to our eyes, and to their well-being.”

Kinross, Modern Typography, page 152

Much lamentable book design is a result of disregard for the well-being of our eyes.