  We describe the feasibility of detecting the gravitational deflection of
light emitted by stars moving under the influence of the massive object at the
Galactic center. Light emitted by a star orbiting behind the central mass has a
smaller impact parameter than the star itself, and suffers the effect of
gravitational lensing, providing a closer probe of the central mass
distribution and hence a stricter test of the black hole hypothesis. A mass of
$4.3\times 10^{6} M_{\odot}$ causes a $0.1-2\rm mas$ deviation in the apparent
position of orbiting stars projected within $10^{\circ}$ of the line of sight
to the galactic center. In addtion, we may uniquely constrain the distance to
the center of the galaxy because lensing deflections constrain the ratio
$\rg/R_{0}$ of the Schwarzschild radius to the distance to the black hole,
$R_{o}$, whereas the ratio $\rg/R_{o}^{3}$ is obtained by fitting the orbit.
