The living human eye is in constant motion. The cornea, which is the transparent front surface of the eyeball, is a formidable specimen for microscopy. How can we use a microscope to obtain sufficient contrast in order to observe cellular and subcellular details on a moving, transparent specimen? Although the normal human cornea is free of blood vessels, there are many nerves within the 500 μm thickness of this tissue. How can we observe these nerves in the living human eye?

To accomplish these aims, use a new real-time, scanning slit confocal microscope that was developed by Dr. A. Thaer for imaging the in vivo human cornea. The optical design of the real-time, scanning slit confocal microscope is shown as follows in Figure 1. The confocal microscope is a modification of the real-time, scanning slit confocal microscope based on an oscillating too-sided mirror (bi-lateral scanning) which was designed and first constructed in 1969 by G. M. Svishchev in Lenningrad.