Can double vision/lazy eye be cured with surgery?

Fixing allignment. If the eyeballs are not aligned properly, double vision will occur. The alignment can be modified by shortening one or more of the muscles that pull the eye into position as it moves. If this is done before the brain decides to stop accepting input from the "lazy" eye, vision can be improved.
Sometimes. Prisms can be used in glasses if the double vision/lazy eye is small to correct things without surgery. If the defect is to large, prisms are not a realistic option.