In hypermetropic anisometropia both farsighted eyes have varying degrees of defects. For mixed anisometropia one eye is myopic and the second hyperopic. With astigmatic anisometropia, both eyes have different values of astigmatism.
The usual recommendation for correction of anisometropia is to wear contact lenses. The effect of vertex distance is removed and the effect of center thickness is also almost removed, meaning there is minimal and likely unnoticeable image size difference.