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In this paper, we first consider null geodesics of a class of charged,spherical and asymptotically flat hairy black holes in anEinstein-Maxwell-scalar theory with a non-minimal coupling for the scalar andelectromagnetic fields. Remarkably, we show that there are two unstablecircular orbits for a photon in a certain parameter regime, corresponding totwo unstable photon spheres of different sizes outside the event horizon. Toillustrate the optical appearance of photon spheres, we then consider a simplespherical model of optically thin accretion on the hairy black hole, and obtainthe accretion image seen by a distant observer. In the single photon spherecase, only one bright ring appears in the image, and is identified as the edgeof the black hole shadow. Whereas in the case with two photon spheres, therecan be two concentric bright rings of different radii in the image, and thesmaller one serves as the boundary of the shadow, whose radius goes to zero atthe critical charge.

Photon Spheres and Spherical Accretion Image of a Hairy Black Hole