###Rationale: Ans. is 'a' i.e., Specular microscope Corneal endothelium is examined with specular microscope, which allows a clear morphological study of endothelial cells including photographic documentation. The cell density of endothelium is around 3000 cells/mm2 in young adults, which decreases with advancing age.

###Answer: OPTION A IS CORRECT.
###Question: Corneal endothelial cell count is measured by ?
###Options:
A. Specular microscope
B. Ophthalmoscope
C. Synoptophore
D. Amsler's grid
