Northampton 78mm Dome Magnifier
(Physical Object)

A dome magnifier is a dome-shaped magnifying device. They are plano-convex lenses: the flat (planar) surface is placed on the object to be magnified, and the convex (dome) surface provides the enlargement. They are good for reading maps or basic text and their inherent 180° design naturally amplifies illumination from ambient side-light. They are suitable for people with tremors or impaired motor skills, because they are held in contact with the page during use.