Thread: determine magnification of reading glasses
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Fred McKenzie Fred McKenzie is offline
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Default determine magnification of reading glasses
In article ,
wrote:

Did you ever find a 'do it yourself gadget to measure power of reading
glasses?

Use the lens to project a distant scene on a sheet of paper. Then
measure the distance between lens and paper to determine the lens focal
length. The shorter the focal length, the higher the power.

Lens power is often expressed in diopters. A diopter is the reciprocal
of the lens focal length expressed in meters. A +1 lens has a focal
length of one meter.

Fred
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