When I open the camera of my iphone 5 the image look blurry

Every time i open the camera app in my iphone 5 the image of what the camera is watching looks blurry, I went to an apple store and one guy told me it was a problem of my phone, but then another guy showed up and told me it was a problem of software. I want to know whats the truth, thank you

Sorry about my english, please answer quickly im from argentina and there's no apple store thereD: