The "clear bubble" you normally see is the cornea. The cornea is a clear living lens that helps to focus light into the eye. You have a cornea on the front of each eye as well. The eye normally contains fluid inside of it with a certain range of normal fluid pressure. If the cornea and/or other part of the eye is punctured, it will actually deflate and this can cause a variety of problems including intra ocular eye infection, retina detachment. It would seem that you don't see the clear bubble on this fish's eye because the eye has been punctured and is deflated. Without the normal shape of the cornea, that eye is undoubtedly blind at this point and is now susceitble to infection. IF the interal eye parts become infected, this can spread to the surround eye socket and brain and cause death. I don't think there's much you can do for a fish in this situtation -- it would need antibiotics by mouth to prevent infection and a suture of the open wound -- never gonna happen. So, not much to do - just keep feeding her and keep good water conditions and hope for the best.
