Open Question: Why did I suddenly change from nearsighted to farsighted?

On Monday, I had discovered that basically over night that my right eye was now farsighted instead of nearsighted. I couldn't read the newspaper at my normal reading distance (everything is blurry), but things in the distance were much clearer. I saw an eye doctor on Wednesday (a new one as my former one does not take my insurance any more) and he basically told me that it was because "I was getting older". While that IS true, I'm 46, it doesn't explain the suddenness of the change. I have never needed reading glasses, but I will now, and this change has something to do with it. My prescription for 1 year ago: L -1.25 R -1.25 My prescription as of yesterday: L -1.00 R +0.25 That doesn't make much sense to me as to how my eyes could just "do that" suddenly without a root cause. I did have pink eye 2 months ago in my rigt eye and took anti-biotics. Additionally, the doctor noticed a scar from the pink eye on my cornea (I believe, some part of my eye had the scar). Any thought to the root cause and can something be done? Many thanks!