2 months ago, I found that I have a red vein in my eye (first picture) so I went to visit the doctor and she gave me Naphcon-A. She suggested using 3 times a day for 1 month. I compared my eye before and after (second picture) using the Naphcon-A and it's redder. Then I googled and found out something called rebound hyperemia. Now I have cold turkey for 1 week and I still have a bloodshot in my eye. Is this bloodshot caused by allergic or rebound hyperemia?