I have been using STAC Eye loupes for the last one year. The quality of these loupes is so good that even at the edge of the depth of view range, the image remains sharp. I am tall and the working distance for these dental loupes is so great, that even I can perform my procedures in the standing position with ease. I have given STAC Loupes to all my hygienists and since then I have not received any complaints about fatigue, eye strain or lower back pain. I have seen productivity improve 25% among my staff. This means higher profits for my dental practice. The customer support is excellent. I will recommend any one to use STAC Eye Loupes as it delivers what it claims for. - Dr. Hog