This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lens, Subject name: Ophthalmology
[{'content': 'SRK formula is used to calculate - \nSelect and explain. \nA. Power of intraocular lens, B. Corneal curvature, C. Corneal endothelial cell count, D. Extent of retinal detachment', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Intraocular lesn power calculation:- Which requires Keratometry (K), Axial length of eyeball or Biometry (L) and a constant (A). It is calculated SRK formula :- (Ref: Yanoff; Jay S. Duker 2009 Ophthalmology 3rd/e p.416-419)', 'role': 'assistant'}]