The year 2020 is an auspicious year—not only because of the importance the eyecare industry places on that particular number—but also because it marks the 100th anniversary of the introduction of the first practical commercial lensmeter for the measurement of effective ophthalmic lens power. The design familiar in form to us today was introduced by American Optical as the Lensometer, which is an AO trademark, after more than 10 years of development. (In this article, the term lensmeter will be used when referring to the generic device, whereas Lensometer refers only to the AO instruments.) Read More