I started my first photobiological research project almost exactly 50 years ago, in the spring of 1957. My scientific interest ever since has been focused on photobiology in its many aspects. Because I have been employed as a botanist, my own research has dealt with the photobiology of plants, but throughout this time I have been interested in other aspects, such as vision, the photobiology of skin, and bioluminescence. A first edition of the present book was published in 2002, but this second edition is much expanded and completely updated. Several new authors have been recruited among my eminent colleagues
