ABSTRACT
A refractive error is an optical defect of the eye that prevents light from being brought to a sharp focus by the cornea and lens onto the retina (154). Varying degrees of decreased vision, low vision, or blindness result from refractive error, depending on the type and severity. If a refractive error is present, it is usually present in both eyes, often to nearly the same degree. Certain refractive errors can be hereditary.
