 Optically-based methods have been developed to detect and quantify Keri's lesions at an early stage, allowing for their rest or reversal before they progress further. These include quantitative light-induced fluorescence, QLF, laser-induced fluorescence, LIF, and near-infrared transillumination of dental enamel, NITDA. QLF has been widely used in research while LIF is commonly used in clinical practice. NITDA is still under development but shows promise. This article was authored by Leina Coulson.