I fell from a 16.3 horse yesterday. This meant my head started over 2m from the ground. I was sat 1.7m up. I was thrown forwards over her shoulder and as I fell I turned and landed on my lower back. Then I got back on for her to do it again 
I landed on the same spot both times. I can sit, lay down and walk though I have to be careful when moving and bending is difficult as it hurts. I also twisted my left ring finger in the reins. That was all obvious last night.
This morning I have noticed blured vision. Up close its not too bad but the further away things get the blurrier they are. As far as I can tell I didn't bang my head. There are no marks at all on my helmet and I fell on hard dusty surfaces both times. I have no headache. NHS website says bluriness is a symptom of a head injury, which I don't think I have, though I have had a blow to my spinal cord I guess. Question is would you get it checked out? If so who by? Call 111, opticians, a&e or somewhere else?