The proper description is a 3 Diopter magnifying lamp. That is NOT the same as a 3 times magnification lamp, or 3x. Diopter is not the same.
When I used a 3 Diopter, I was not satisfied until I found a 5 Diopter, and when I got that, I went searching for better, until I found a 9 Diopter, the 9 was better for vision, but had to be too close to the work area to be practical for some work.
After shelling out for all that, I got some loupes, and they were better, but did not have a light source mated to the system, and the focal distance required me to move my body into a position and hold it if I was going to see clearly. This caused much eye strain due to blurry vision and shaky body positions.
When I shelled out for a stereo microscope, I found better vision (first 20 x’s magnification, and now 40x’s mag) and the light source was mated to the vision equipment, so what ever you are looking at, the light moves with you, and finally, the arm holds the vision equipment at the correct focal distance, as long as the client doesn’t move around too much.
This leads to less eye strain, and can lead to better working posture if you get the working distance of the lens set well for your own personal needs.
We found that Dee can’t use my scope comfortably, because with a difference of about 7 inches in height, and my longer arm reach, she can’t get into a comfortable position to work at the focal distance that works for me.
This is why I love the Stereo Microscopes. Now if I could just get the magnification of a Zeiss Opmi 1 into the framework of a Zeiss Opmi-99, I would be deliriously happy.