In one of the best literary non-fiction books of recent years, she tells children about the things that they can spy with their little eyes – and about all of the tricks that your eyes can play on you. The intriguing title Thinking Half a Dog Whole (Een halve hond heel denken) is a reference to one of the phenomena that Van Leeuwen discusses in the book: the fact that we sometimes “see” more than is actually in the picture. In her usual clear and captivating style, Van Leeuwen explains that it’s all the work of our imagination: “Our eyes receive what they see and our brains compare that with what they already know.” In other words, we see a picture of half a dog and complete the rest in our minds. But there are also times when we see less than is in the picture, because we take so much for granted when we look at everyday objects. As Van Leeuwen says, “Sometimes you really can’t tell whether what seems real actually is real.” This fascinating theme connects the thirteen chapters, in which Van Leeuwen presents a lively picture of a wide variety of subjects, including advertising, the history of drawing, medieval symbolism, the golden ratio, how the eye works and a chapter “about visible and invisible lines and how they help and point and sometimes even look shy”.

All of this makes Een halve hond heel denken a very accessible, wonderfully colourful book. So, open your eyes, take a look and be amazed.