Layton was sporting the eye patch for a while. Then, he was going to go swimming, so what was he to do? He put the goggles on top of the patch.
Maybe this isn't the most functional look he's ever had, but it served his purpose. He got to keep the eye patch and got to swim with goggles. He is obsessed with wearing goggles in the pool, so he can open his eyes without them burning from the Chlorine.