Solar mirrors for concentrated solar power (CSP) plants are expected to last at least 30 years. As this delay is far too long to obtain useful information regarding in-service degradation, accelerated approaches to weathering testing are performed by manufacturers and research laboratories in order to quickly assess the lifetime of commercial or new technologies. However, most published studies that have been performed in the CSP field are based on phenomenological approaches. The characterization of the degradation, which mostly considers reflectance loss, has rarely been linked to physical or chemical processes that are responsible for the degradation of properties. Furthermore, the general laws that can be established from these data to establish material behaviour are empirical. Ageing tests have been used for many years in other fields, particularly in the domain of polymeric materials. The impacts on the material properties of stress factors such as temperature, irradiation and humidity have been extensively studied, and models have been proposed for different kinds of materials, even though most are based on empirical observations. One of the goals of this article is to determine how these models could be applied to the weathering of solar mirrors, and as such, the goal of this paper is to provide a critical review of the various models that are most used and accepted by the scientific community. All of these models include material-dependent parameters, and the values that have been determined in these studies are reported here to list their order of magnitude.