The profession is often regulated by optician-specific agencies, as in Canada and some states of the U.S., or jointly with optometry such as the New Zealand Optometrist and Dispensing Opticians Board or the United Kingdom General Optical Council. Opticians may work independently or dependently with an optometrist or ophthalmologist although some opticians may work in an optical laboratory as a laboratory technical optician. Opticians convert a prescription for the correction of a refractive error into an ophthalmic lens or some other device, such as reading aids or telescopic lenses.[4][5][6]