What Caused Blurry Vision During My IV Treatment For An Allergic Reaction With Severe Abdominal Pain And Dehydration?

Hi! Yesterday I was in the hospital for an intense allergic reaction with severe/crippling abdominal pain, and dehydration due to constant throw up. I had to get an IV for fluids and cramps medication, while I had the IV on I got such a blurry vision that I could not see anything in front of me the whole time. What could that be?