Turbidity is increasing in freshwaters globally due to human activities and is known to affect visually-mediated behaviours in fish. As anthropogenic impacts continue to degrade aquatic environments, it is critical to determine how sensory systems are affected and what this might mean for population persistence. We investigated visual morphology and opsin gene expression in an African cichlid fish (Pseudocrenilabrus multicolor) that experiences environmental extremes across its East African rang