The only reason for a corn to develop on the top of a toe is because of an ill-fitting shoe rubbing the toe. Buckled /clawed toes are particularly vulnerable and therefore such toes should be accommodated in shoes with a deep toe box.
Laced shoes generally provide a greater depth within the toe box, slip on shoes will generally provide the least amount of depth within a toe box.
Note the presence of necrosis/ulcer and pus from an infected corn
Note the protective felt pad wrapped around the corn site. This will protect the area from an ill-fitting shoe
a) Apical Corns