Terms to understand to truly appreciate the features of our magnifiers:

• What is a Diopter? This refers to the curvature of the lens, which, in addition to the thickness, becomes greater as the diopter increases.
• What is Power? This refers to how much larger an object is made to look through a magnifying lens. For example, a 3-diopter lens makes an object look 75% bigger than what the unaided eye sees, when held at a distance of 13 inches below the lens.
• What is Focal Length? This is the distance from the center of a lens to the point where the light rays converge and the object is in optimal focus. In our example of the 3-diopter lens, the focal length is 13 inches; a 5-diopter lens would have a focal length of 8 inches.
• What is Field of View? This is the size of the magnified area under the lens that is in focus, which decreases as the power increases.