This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Ophthalmology
Astigmatism in emmetropic eye of elderly person contribute to: 
Select and explain. 
A. +1d, B. +2D, C. +3D, D. +4D
C: +3D
Answer: C: +3D 
Explanation: Laser vision enhancements When planning presbyopia-correcting IOL(Intra ocular lens) surgery in a patient with a high level of pre-existing astigmatism (ie, more than 3 D), a bioptics approach (ie, IOL followed by laser vision enhancement) may be needed. LRIs alone are unlikely to correct the astigmatism completely.Limbal Relaxing Incisions (LRI) are a refractive surgical procedure to correct minor astigmatism in the eye. There are several different strategies for these planned laser vision enhancements. The first is to perform the presbyopia-correcting IOL surgery followed by LASIK or PRK. REF : AK KHURANA 7TH ED