Corns develop on the toes when the medium to long term pressure on an area. The skin thickens in response to that pressure, but becomes so thick that it becomes painful. The only way to permanently get rid of corns is to remove that cause.
Most Useful Resources:
Corns on Toes (Foot Health Forum)
Painful corn on toe (Foot Health Forum)
Corn on toe(Foot Health Forum)
Foot Corns & Callus (hyperkeratosis) (ePodiatry)
Corns on the Toes (Dr the Foot)
What causes corns on the toes? (Foot Health Friday)