I see a man's life is a tedious one. Cymbeline, Act III, Sc. 6. It is
well known that the best way to learn a subject is to teach it! Along
the same lines one might also say that a pleasant way of learning a
subject and at the same time getting to know quite a few of the workers
active in it, is to arrange and to attend an Advanced Study Institute
(ASI) or a workshop lasting about two weeks. This was and is the wisdom
behind the NA TO-ASI programme and much as people fear that a fortnight
may be too long, before it is over everyone feels that it was too short,
especially if the weather had cooperated. Organising this ASI which
resulted in this volume has been a very good learning experience. I
started my career in research with invertebrates and retained an
interest in them over the years due to my teaching a course and working
sporadically on various aspects of photoreception in Polychaetes,
Crustaceans and Insects. Thus, the thought of organising an ASI on
photoreception and vision in invertebrates had been brewing in my mind
for the past half a dozen years or so. It was felt that it will be
desirable to do a bit of stock taking and discuss possible new
approaches to the study of this matter.