dome magnifier

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A dome magnifier is a dome-shaped magnifying device made of glass or acrylic plastic, used to enlarge words on a page or computer screen. 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 usually provide between 1.8× and 6× magnification.{{cite book|last1=Albert|first1=Daniel M.|last2=Jakobiec|first2=Frederick A.|title=Principles and practice of ophthalmology|date=2000|publisher=Saunders|location=Philadelphia|isbn=9780721675060|page=5433|edition=2.}}{{cite book|title=Assistive Devices for Reading Issue 93, Part 2 of Reference circular|date=1993|publisher=National Library Service for the Blind and Physically Handicapped, The Library of Congress}} Dome magnifiers are often used by the visually impaired. 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.