First we meet all the different people who work at the opticians' practice, and then we meet Amber and Ben, who, with their father, make appointments for an eye test. There is lots of information about the eye test and all the many pieces of equipment used, and we see Amber and Ben being tested. Big words are explained, both in the text and in the glossary at the back. We are even shown how lenses are made. Simple large-print sentences and clear photographs make the information accessible. As well as the glossary, there is an index, a list of websites, and a series of questions having to do with what the book has told us. This is a good introduction to what to expect when one must have one's eyes checked.