LASIK is one of the most commonly performed refractive surgeries worldwide because of patient’s comfort and surgeons skills. This young generation undergoing LASIK surgery will also have to undergo cataract surgery in their old age. Patients undergoing cataract surgery require intraocular lens (IOL) calculation for the IOL implantation. As LASIK changes the corneal curvatures the keratometry and effective lens position will be affected leading to change in IOL power. This study aims to identify the change in IOL power after LASIK surgery. Method: We performed a prospective and observational study on 75 patients (150 eyes) undergoing LASIK surgery, who met inclusion criteria. All the patient were categorized on basis of degrees of myopia and all went under same preoperative and postoperative treatment and data was collected using performa. Additionally, axial length of all the cases was measured before and after LASIK, also same techniques were used to measure corneal parameters postoperatively. All the collected data were used to see the change in IOL power before and after LASIK. Conclusion: IOL power after LASIK surgery changes significantly due to changes occurring at the level of cornea. Higher the degrees of myopia more the difference in IOL power was be seen. The mean increase change in IOL power among 150 eyes using SRK I was 2.95 D ± 1.20, while in SRK II, SRK T, Hoffer Q, Holladay and Binkhorst was 3.03 D ± 1.41, 3.45 D ± 1.45, 4.73 D ± 1.91, 3.91 D ± 1.55 and 4.57 D ± 1.80 respectively. Over all maximum change was seen in Hoffer Q and minimum change in SRK I formula. All the formulae mentioned may produce residual refractive errors, for that the patient has to undergo cataract surgery, but we have only taken the postoperative LASIK patients so it cannot be confirmed which formula yields the least residual refractive error after cataract surgery in post LASIK eyes.