Consistent tillage will help reduce the fungal presence, but the most effective method for control is to rotate away from corn each year. One year will allow the corn residue to decay to a point where fungus levels will not be an issue.
Fungicide application can be effective if used early on in an epidemic, especially in seed corn that in a reduced tillage field. It's only recommended if the previous year had eyespot infections, but always consider resistant hybrids as the number one option. Please contact your local plant pathologist to learn what is most effective in your area and how to use it best. Always read and follow all label instructions.
Plant corn hybrids that have at least some resistance to eyespot. There are available varieties.