Will I always need a patch for my left-eye dominance?

I'm a lady gun and have just begun shooting. I'm left-eye dominant and my instructor demonstrated that a small patch or piece of tape on the lens of my safety glasses would help with this problem.

How can I help my eye dominance problem?

When I was younger I had a very dominant right eye, but as I have grown older I have developed a very pronounced master eye problem. Short of closing my left eye when I shoot, is there some other mechanical means that would help me? I do nowadays wear prescription…