Only Single Eye Observation: We recommend using only one eye of the double-eye loupe glasses to view the object, because when using two glasses at the same time, the focus will fail. You can use the two lens barrels alternately to eliminate visual fatigueand effectively improve your work.Please note: This magnifying glass is suitable for close-range work, please stay closer to the target observation object. Detachable: The bracket and headband are interchangeable, both can be worn firmly and reduce fatigue during long-term use. And the adjustable magnifying glass bracket can be flipped up and down, you can flip to the desired position to ensure that theeyeball is in the middle position, you can see the details more clearly. Before use, it is recommended that you can flip the front lens up to use a single lens. Versatile Applications: The head-mounted magnifier with light has a wide range of usability, which is very suitable for close work, such as reading, watch/circuit repair, crafts, jewelry identification, eyelash extension, welding, painting, etc. It isvery suitable to help watch repairers, jewelers, the elderly, short-sighted or short-sighted people observe nearby objects.