How hit the eyes in order to get the master key in phantom hourglass?

If you mean de closing eyes in the Temple of Ice:

Stand on the long middle piece of ground, then attach the grappling hook to the two poles.

Then shoot arrows at the rope, wich will bounce of in direction of the eyes.

Once you've shot the eyes, a chest will appear. To get of the platform you're on, shoot the grappling hook on the chest