How to Adjust Loupes?

Hi Guys,

Loupes are used within the surgical and dental professions as a magnification device. Loupes can use for intricate, close-up work, such as model painting. Loupes are also useful as it can adjust the angle of the magnifying lens to point downward so it can stand upright and still look down at what it is working on. However, improving its posture and helping prevent neck and back pain. I want some instructions that loupes are adjust in surgical. Hope all will give best tips to me that will best for my profession.

Best Regards,
Simon Joseph