What does corns look like?

Clinically, corns are round or oval horny hyperplasia, generally as large as beans or larger, with clear boundaries, flat or slightly convex surfaces, inverted conical, inward at the top, sometimes embedded in the dermis. And scrape off the cuticle on the local surface with a knife, and see a hard horny plug in the center, surrounded by transparent pale yellow rings, shaped like corns. Corns normally grow on the foot mostly due to local friction, so when corns occur, the foot is usually accompanied by painful symptoms when walking.