Figure 2.
The endothelial cell area is a compromise between the width of the light beam and the thickness of the cornea 54. As the narrow slit light beam show in Figure A is broadened the light reflex can be seen from the rectangular epithelial and endothelial surfaces. As the slit width is increased further the epithelial surface reflex will encroach upon the endothelial reflex as shown in Figure B.