Fusarium is a widely spread fungus that affects small cereal grains mostly during flowering and thrives in warm, moist conditions. Fusarium head blight diminishes the nutritional, physical, and chemical qualities of the grains, which consequently lowers their market value. Mycotoxins are toxic, secondary metabolites produced during the fungal infection process and are not eliminated by industrial processes such as milling, baking, malting, or ethanol production. Above certain levels, mycotoxins can have toxic effects in humans and livestock. Therefore, Fusarium monitoring is extremely important to avoid potential mycotoxin production. Optical techniques are recognized as one of the best ways to assess a batch of samples in a fast and non-destructive way. Previous reviews on Fusarium assessment have provided an overview of all the possible methods for its detection, while others list Fusarium as one among several known plant diseases and provide some applicable methods for safety inspection of food. This paper reviews current techniques for grain quality assessment, particularly a thorough appraisal of the optical methods and classification algorithms applied to identify and determine the infection level of Fusarium spp. Hence, this work highlights the latest literature concerning Fusarium and deoxynivalenol identification and currently used methods to determine levels of infection.