Eye sight

Has anybody ever had perfect eyesight then a few years later started having eye sight problems? I had an eye exam 5 years ago and my vision was perfect 20/20. Over the last year I have noticed more and more that I am having trouble reading street signs and the TV guide ect. Reading has become more blurry. It feels so strange. Not sure if this is normal and it happens or if it is a sign of a more serious issue. I am only 21.