What could cause sudden blurry spot in vision?

What could cause sudden blurry spot in vision?

• Yesterday I felt fine then noticed a blurry area in my vision. I thought maybe I had something in my eye but when I covered one eye, the spot was still in the other, with both eyes. Which led me to think this must me something going on in my brain, not my eye itself. Also, no mater what object I focused my vision on, the blurry spot was to the right of whatever I was focusing on. The blurry spot also seamed to have movement, like it looked as if there was a flashing light in the area that was blurry. The area of blurriness was shaped like a backwards letter "c". It only lasted like 30 minutes then my vision totally went back to normal and hasn't gotta blurry since. I'm just wondering what could have caused this and should I be worried. For some extra info - I'm 24 years old, do not smoke, I do not wear glasses and have never had any eye/vision problems, the only medication I'm currently taking is oral birth control and allegra. The only other thing I was thinking, is could it be astigmatism? I do ride horses and have rode my whole life and have heard that makes you more prone to it but I don't really know anything about it. Also, the reason I have not gone to the doctor is because my doctor is over an hour away, I live in a very rural area. But if this is something serious I may consider going to get checked out. Thanks for any advice!

• Answer:

  this sounds like something i get called Scintillating scotoma which in most people preceeds a migraine. however i get it with no headache because i have a demyelinating disease which attacks the coating that protects the optic nerve. if this starts to happen more get it checked it may be serious.