All three of these sentences have some grammatical errors in them. The best way to say what you're trying to say is: "I think you may be going blind."

A problem with this is that *eyes* do not go blind. People go blind. So it is not really correct to say even: "It seems that your eyes have gone blind." It is much better to say either a) "It seems that you have gone blind" or b) "It seems that your eyes have gone bad."