Ten years have passed since 1984, when my previous book on blindness and children, Blindness and Early Childhood Development, was published. Those ten years have seen a welcome surge of research on children with visual impairments, and that is reason enough to write a sequel. But Blindness and Children: An Individual Differences Approach is not just a sequel. It takes an entirely different approach to analyzing the research literature. As the title suggests, this analysis and summary of the literature is based on the premise that it is the variation within the population of children with visual impairments that we should be studying, not the norm. I believe that a truly useful body of research-based knowledge about this population must focus not on the norm, or the usual, but on the unusual. It should focus on children whose development is unusually advanced and on those whose development is unusually delayed. It should focus on the factors in those children's experience that have caused their development to vary in a positive or negative direction. Only with that kind of knowledge base will we be prepared to intervene in the lives of children with visual impairments in order to allow them to achieve their optimal potential.

Above all, the message that this analysis contains is one of optimism: optimism on the part of researchers that they can provide service professionals and parents with sound advice about how to structure children's experiences; optimism on the part of service professionals that their expertise can make a positive impact, rather than just avoid a negative outcome; and above all, optimism on the part of parents that their children with visual impairments need not be bound to the delayed development that our current norms suggest, but that if provided appropriate environments and experiences, these children can truly achieve an optimal developmental course.