Can the sunken inner corner of my eye be fixed with filler? (Photo)

It depends upon which area of the eyelid you are talking about. I wouldn't inject filler in the area of your epicanthal fold (right by your medial canthus) because this could cause an unnatural appearance of the medial canthus and normal fold in the eyelid. Potentially a small amount could be injected more laterally to address some early volume loss but this would require very careful and precise injection technique.

The space between the nose and the inner portion of the eye is meant to be somewhat hollow. Filling out this area will make you look extremely bizarre. I would not recommend doing that at any cost. I hope this helps and good luck from New York City plastic surgery