The core portion of this trial unit developed by the Australian Science Education Project provides activities from which students gain experience in the formation of images by water and glass lenses. Additional optional sections of the unit contain suggested activities and questions which lead to a study of mirrors, refraction, eyes and spectacles, the nature of color, microscopy, photography, and the production of apparently continuous images from discrete points. The teachers' guide lists objectives for the core and each option, suggests suitable teacher and student references, and lists the apparatus required. Hints on classroom management, including topic introduction and consolidation, are included. The students' book also provides instructions for the production of simple apparatus and suggestions for out-of-school follow-up activities. A question book containing a diagnostic test to be used at the completion of the core, a booklet containing annotated answers to these questions, and a set of posters are also included in the package. (AL)