In some people the changes are slow and in others its fast. With very rapid changes other things need to be considered like diabetes or the effect of some medications or corneal disease.
JCH MD
Yes, it's possible! Last year this happened to me (my vision in my right eye started appearing blurry almost overnight at one point and I didn't know what was wrong). I went back to the eye doctor and they diagnosed it as a condition called keratoconus (would fall in the corneal disease category mentioned by the MD above me). I don't say this to worry you because that was my unique circumstance, but it could be a number of things so you should go back and get it checked out. In my case they prescribed a new contact lens that allowed more oxygen to get to my eye. Most likely the doctor will have an explanation for you!