I am the same problem too. Don't worry. You can go to the private eye doctor to check. It is not very expensive. I went to the Precious Blood hopsital. It cost me about $250 only.
But if you go to check, you have to pay attention to the following point. To check it, they will drop some eyedrop into your eye to enlarge the iris. Since it takes a few hours to let your iris contract back to normal size, your eyes will feel quite tired and scared of brightness. It is better not to go anywhere after the eye check.