This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea, Subject name: Ophthalmology
Fluoresciene stain is used in the eye to stain - 
Select and explain. 
A. Cornea, B. Retina, C. Choroid, D. Iris
A: Cornea
Answer: A: Cornea 
Explanation: Ans. is 'a' i.e., Cornea Important corneal examinationsUsed foro Keratometry, Corneal topography o Specular microscopyo Slit lampo Padiymetero Placido's disco Fluorescein. Alacian blue & Ben sal rose staino Window reflex, slit lamp biomicroscopy, Placidos' discCurvature of cornea Corneal endothelial densityCorneal opacity Thic kness of cornea Corneal sheen Corneal stainingCorneal surface