Take a shower, wash your hair and face, run lots of warm water. From any drug store you can get artifical tears and sterile eye rinse. You can put these right on the eye to flush it and then every 15 minutes for a couple of hours. If the pain is not bad and the vision not bad and the eye looks only a little red you can probably see how it does over the next 12 hours. Gasoline is not extremely toxic to the outside of the eye.
JCH III MD
It is always advisable to seek medical attention whenever these things happen. If you're still having complications, then it means something my be wrong or even a sign of an underlying condition or infection. Please check it out!