Private hospitals are investing more in advanced medical equipment in order to compete in the domestic health care market. Bright Eye Hospital Group, a private medical group, said on Saturday it had bought four advanced optical surgery machines from Germany. With the first surgical microscope and the first commercial optical coherence tomography, or OCT, for ophthalmic applications, the ZEISS RESCAN 700 gives doctors continuous real time visualization of corneal changes during surgical procedures. The accuracy is one tenth of hair.