  We study gravitational lensing of light by hairy black holes, which, in a
certain parameter regime, can possess two photon spheres of different size
outside the event horizon. In particular, we focus on higher-order images of a
point-like light source and a luminous celestial sphere produced by strong
gravitational lensing near photon spheres. Two photon spheres usually triple
the number of high-order images of a point-like light source. When a hairy
black hole is illuminated by a celestial sphere, two photon spheres would give
rise to two critical curves in the black hole image, and the smaller critical
curve coincides with the shadow edge. In addition to a set of higher-order
images of the celestial sphere outside the shadow edge, two more sets of
higher-order images are observed inside and outside the larger critical curve,
respectively.
