This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Lens power.svg Diagram of how to determine the power of lens from its focal length assuming parallel incoming wavefronts en Transfer was stated to be made by User Mike lifeguard br original text own work br original text Sjlegg en en Sjlegg original upload log page en Lenspower svg Sjlegg bytes no Sjlegg bytes no