The magnification of a magnifying glass depends on where it is placed between the user's eye and the object being viewed, and the total distance between the eye and the object. Magnifying glasses are typically described in terms of their magnifying power, which is equivalent to angular magnification (this should not be confused with optical power, which is a different quantity). The magnifying power is the ratio of the sizes of the images formed on the user's retina with and without the lens.[2] For the "without" case, it is typically assumed that the user would bring the object as close to the eye as possible without it becoming blurry. This point, known as the near point, varies with age. In a young child it can be as close as 5 cm, while in an elderly person it may be as far as one or two metres. Magnifiers are typically characterized using a "standard" value of 0.25 m.

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