A disproportionate amount of the human genome is involved in some way in the development or function of the eye and visual system. Hereditary and genetic diseases of the eye therefore represent a significant workload for paediatric ophthalmologists. Many developmental abnormalities will present to the ophthalmologist either at birth or in early infancy. Some genetic eye diseases may evade discovery until later childhood when they present for the first time to the optometrist. The following article highlights some of the hereditary diseases that an optometrist might encounter in children with visual loss. It is not the intention to provide a comprehensive list of genetic eye disorders but what follows is based on the author’s experience of the type of children’s disorders frequently referred by optometrists. In the first part disorders of the retina and optic nerve will be discussed. The second part will highlight whole-eye and anterior-segment disorders.