Usually if you are going to have your eyes checked, you go to a doctor called an " optometrist, " but if you are just buying glasses, then you would go to an optician.
天文学百科 The Astronomy Book (Big Ideas Simply Explained)
After 1820 German optician Josef von Fraunhofer builds a new type of heliometer, a device for measuring the Sun's diameter, for the study of stellar parallax.