What is the best over-the-counter treatment for eczema on the face?

Treat dry skin. Treating the dry skin often will get rid of most of the eczematous areas. Aquaphor is an extremely greasy lubricant that is often needed to treat moderate to severe eczema. Steroid creams like Hydrocortisone may be needed as well, but they can cause patchy discoloration of the face and so should be used with caution.
Cortisone. Otc 1% cortisone cream is perfectly safe to use on the face. I've also seen my eczema clients skin improve with increased vitamin d intake. In ohio 90% of my patients have low vit d levels.