https://creativecommons.org/publicdomain/zero/1.0/https://www.rawpixel.com/image/14000056Edit ImageSaveSaveEditCropCustom TextA diagram to show the principle of Helmholtz's ophthalmoscope. Pen and ink drawing.Original public domain image from Wellcome CollectionMorePublic DomainFree CC0 image for Personal and Business useInfoView CC0 LicenseJPEGSmall JPEG 1200 x 1104 px | 300 dpiLarge JPEG 2844 x 2616 px | 300 dpiFree DownloadA diagram to show the principle of Helmholtz's ophthalmoscope. Pen and ink drawing.More