I need to find a photo of the eyes on a dahlia tuber.
There is good information on growing dahlias, including an image of the location of the eye on a tuber, at the website of the American Dahlia Society. To find the eye, locate the point on the shoulder, or crown, of the tuber from which the plant grows. The blog of Lynch Creek Dahlias (now archived) has good description and illustrations:
“Keep in mind that every dahlia tuber, to be viable, must have at least one eye, which you’ll see as tiny pointed protrusions on or near the neck of the tuber (the neck is the tuber’s connection to the central part of the root mass).”
The Dahlia Barn website also has images and instructions, as does the Summer Dreams Farm website.