The Visconti Hours is a 14th century book of hours. A Book of Hours is a compendium of devotional texts that takes its name from its one essential text, the Hours of the Virgin, or more properly the Little Office of the Blessed Virgin Mary. Despite the lack of perspective in the medieval images on these pages, we can see that the book is becoming a repository for naturalistic study of plants and animals. In the Book of Kells there is an other-worldly truth. In these works, we see a this-worldly presentation.
Similar themes show up in other religious texts.
The creators of these works are also beginning to include images of their own social world. In this manuscript, the Hours of Catherine of Cleves , produced in 1140, there is a picture of the Holy Family with Christ in a walker. And there is a new kind of realism. Religious images begin to look more like what we would see today, with a more modern notion of both perspective and scene - with the sheep and the dogs in the picture with the angels and the shepherds. In other texts like the Tacuinum Sanitatis , published in the 10th century, there is a clear image of the real world, without any religious significance.