Scleral congestion is one of the manifestations of inflammation of the sclera. Degeneration, necrosis, inflammatory cell infiltration and granulomatous proliferative reactions in the collagen fibres of the sclera due to various etiologies can cause blood vessels to proliferate and dilate and become congested, forming inflammatory nodules or diffuse inflammatory lesions. This is known as scleral congestion or small nodular hyperplasia visible to the naked eye.