Optical biometry fundamentally revolutionized cataract surgery. 2019 marked the twentieth anniversary of the launching of the first optical biometer. Professor Adolf Friedrich Fercher’s visionary ideas laid the basis for the development of optical coherence tomography (imaging technique using a special frequency of light). In 1982, Fercher’s patent allowed Zeiss to produce and launch the IOLMaster in 1999. This was the first time a noncontact and much more accurate diagnosis of the human eye was possible without touching the cornea. Today, optical biometry is the standard method and an indispensable part of ophthalmology.