During embryogenesis, the vascular supply to the developing lens regresses. Failure of this process results in the presence of visible (& in some cases patent) vascular remnants, associated with the lens and/or lens capsule, typically leading to cataract formation and visual impairment. Findings associated with this condition have been described as persistent hyperplastic tunica vasculosa lentis / persistent hyperplastic primary vitreous (PHTVL/PHPV). Commonly affected breeds include the Doberman Pincher, Greyhound and Staffordshire Bull terrier.