The editors have assembled an impressive authorship to produce this book on development of the retina. There are several reasons why this is timely. Over the last decade there have been rapid advances in our understanding of the mechanisms involved in formation of the eye and determination of the fate of cells. This has been driven by an explosion of laboratory techniques that have allowed the study of gene expression and characterization of cell and tissue behaviour.

As a consequence there is increasing knowledge of what determines cell function, and of the behavioural relationship between cells. This has resulted in an understanding of genetically determined disease in humans. Many genes' products have been identified during development because they are highly expressed and mutations in these genes have been identified as being responsible for developmental abnormalities in man. Some of these genes express at low levels in adult life fulfilling a house-keeping function, and mutations in these have also been identified as giving rise to progressive retinal degeneration.

Findings from studies of development are of crucial importance to the current attempts to devise biological treatment of retinal diseases. There is ample evidence that growth factors delay cell death due to apoptosis in genetically determined retinal dystrophies in animals, and therapeutic trials in man have been initiated. There is still some doubt as to which agent may be the most appropriate to achieve suppression of apoptosis.