IIRC that wasn't the point of the eye. Jumps and such are aetherically enhanced in the same way all the other physicals skills are, using the "caster's" own aether. The eye makes the user stronger, which is why they get the fancy Azure Dragoon title, but it's not the main source of dragoon power. All DRGs can jump. The eye just let Estinien do it better that everyone else. A power he retains, having absorbed the remaining energy from the eyes at the end of 4.0. (The WoL replicates this simply by having an absurdly huge amount of aether compared to most people.)

Fun fact: The wings and fins on DRG gear are actually flight stabilizers for more powerful and accurate jumps.