The discovery that myopia can be induced in animals has resulted in renewed interest in the condition and it is hoped that information gained about the production, manipulation and prevention of myopia in animals might provide information about naturally occurring myopia in humans. Early experimental work was carried out using monkeys as subjects, but the high cost involved, and the difficulty of obtaining monkeys in adequate numbers for good experimental design and control, made researchers look for more suitable experimental animals. Myopia has also been induced in other animals species such as the domestic cat, the tree shrew, the marmoset, the guinea pig and, most successfully, the domestic chicken. The parallels between experimentally induced myopia, which can only be induced in infant animals, and human myopia which typically develops well after infancy, have still to be established.