What lens shapes are available on illuminated magnifiers, and what are the advantages and disadvantages of each?
Illuminated magnifiers come with one of two lens shapes: round or rectangular. Until twenty years ago, all illuminated magnifiers featured round lenses. In addition to being relatively inexpensive to manufacture, the round shape proved convenient for use as fluorescent light sources at the time were also round. Once non-round-shaped compact fluorescent light sources were introduced however, the importance of maintaining a round shaped lens lessened and the interest in developing rectangular lenses increased. In 1987, Luxo introduced the first rectangular lens illuminated magnifier. The primary advantage of a rectangular versus round lens is increased field-of-view. Wide-view rectangular lenses allow a greater viewing area than round lenses which force the user to rely solely on the center, undistorted section of the lens for optimal magnification clarity. For example, on a typical 5″ diameter round lens, only a 3″ diameter field-of-view in the center of the lens is usable. This means t
