If light passes near a massive object, the gravitational interaction causes a bending of the ray. This can be thought of as happening due to a change in the
effective refractive index of the medium given by n(r) = 1 + 2 GM/rc2 where r is the distance of the point of consideration from the centre of the mass of the
massive body, G is the universal gravitational constant, M the mass of the body and c the speed of light in vacuum. Considering a spherical object find the
deviation of the ray from the original path as it grazes the object.
n(r) = 1 + 2GM/rc