The first volume of a three-volume complete edition of Newton's optical papers contains his Optical Lectures, delivered at Cambridge University between 1670 and 1672. The Lectures is Newton's first major scientific treatise, and consequently it represents a crucial link between his early years of discovery and his mature investigations and publications, such as the Optiks in 1704. It is divided into two parts: the first part devoted to color and the second to refraction. Originally published in 1984, this edition made available the complete text, together with translation and commentary, of both surviving versions of the Lectures, a draft and a vastly expanded revision. Until the time of publication, scholars had to depend on an uncritical text of the revision and an inadequate partial English translation, both published shortly after Newton's death. Professor Shapiro's critical edition has made a great contribution to the study of Newtonian science.