Intrauterine or infantile hypocalcaemia may be responsible for congenital or infantile cataract. This may advance to maturity if the hypocalcaemia is untreated, or may be arrested at the stage of a lamellar cataract, whose location in the lens indicates the time of the metabolic insult. They are frequently bilateral.

Calcium ions have a profound effect on membrane permeability and it is likely that the cataract is produced by an increase in lens fibre membrane permeability produced by hypocalcaemia.