Different iLASIK prescriptions from 2 eye specialist centres - what should I do?

I'm interested in doing iLasik, so I went to an eye specialist where I was told that my eye power was -5.00 and -4.75 with my left eye as my dominant one. I'm a contact lens wearer, and the last eye check I had, my power was -3.75 and -4.00. I went to get a second opinion about my entire candidacy, not specifically for my eye power only and they said my power was -3.75 w/ my right eye as the dominant. What should I do? Frankly I trust the first centre more as the tests were machine-based