Double vision from left eye?

I noticed that everytime i try to focus on something, like reading small prints, my left eye seems to shift inwards more. I notice that everything in the background on the left side starts to look double, and when i try to stop focusing on an object, i actually feel my left eye going back into place (it sort of feels heavy). I asked my sister to observe me while looking at my finger and she noticed that my left eye was the only one shifting inwards. Does anyone know what this is?
NOTE: its only when i try to focus on something closer.

[Ray T Oyakawa, MD]

You are hyperopic and need glasses.  See an ophthalmologist.

Dr. O.