SHEET AND BAR MAGNIFIERS
What is commonly referred to as a Sheet Magnifier is actually called a Fresnel Lens or a Fresnel Magnifier. Sheet Magnifiers are made by molding or stamping a series of annular optical grooves on to a flat sheet of acrylic or PVC. Sheet Magnifiers use far less material than a typical double-convex magnifier making them far more attractive as Bookmark Magnifiers or Wallet Magnifiers. However, Sheet Magnifiers also reduce image quality, so they work well for glancing at a menu or a phone book, but they are not recommended for intensive study. Bar Magnifiers are used by resting the magnifying device directly on top of the viewing area. By 'stretching' the text from top to bottom, a Bar Magnifier often allows the user to view text that could not otherwise be seen. Bar Magnifiers are most commonly used for reading or to follow needlework patterns.