  We investigate gravitational lensing in the context of the MOG modified
theory of gravity. Using a formulation of the theory with no adjustable or
fitted parameters, we present the MOG equations of motion for slow,
nonrelativistic test particles and for ultrarelativistic test particles, such
as rays of light. We demonstrate how the MOG prediction for the bending of
light can be applied to astronomical observations. Our investigation first
focuses on a small set of strong lensing observations where the properties of
the lensing objects are found to be consistent with the predictions of the
theory. We also present an analysis of the colliding clusters 1E0657-558 (known
also as the Bullet Cluster) and Abell 520; in both cases, the predictions of
the MOG theory are in good agreement with observation.
