The first priority is a personal consultation with an optician. As every person is an individual, his or her eyes and viewing behaviour are also unique. As a result, a qualified optician will do an exact eye care analysis. For example, he will ask, about your job and hobbies, in order to get an idea of your viewing habits. Your posture and the shape of your head are also taken in consideration during the consultation.Precise vision testing plays a special role in making progressive lenses work perfectly. Not only are both eyes individually measured, binocular vision is also tested to determine the necessary lens power. Only by doing this can the suitable reading and distance powers be determined.Precise fitting measurements are also necessary. The center of the pupil must be aligned to the center of the spectacle lens in order for the lens to work properly. For more sophisticated progressive lenses, additional measurements may be needed.