Can a very dry eyes cause duple vision ?

Duple vision? Are you meaning DOUBLE vision? No, I have never heard of that being a Dry Eye Syndrome symptom.

It depends on what kind of double vision you have. There are 2 kinds. true double vision is when your eyes are misaligned and look slightly different directions. In this case, if you covered an eye, you'd see single again. In which case, would be completely unrelated to severe dryness and you should go see an eye dr to check that out.

If your cornea was so dry that there was significant damage on the surface, you could get distorted vision that could be described as double vision. If you covered an eye and still saw double this could be the case.

Either way, treat your dry eyes with artificial tears and possibly night time ointment if it's that bad.