How can I reduce the double image seen when looking through binoculars? I recently got a new pair, but have been having troubles using them because I am seeing double...
The double image is almost certainly because you have the axes misaligned with your eyes.
The three adjustments you can make are (usually):
(sometimes you have totally independent focus, but the above is more common)
The focus options will make things blurry, but having the barrels too wide apart, or too close together can mean your eyes can't easily resolve to a single image.
try adjusting the separation first. If that doesn't help, it is possible you have a badly aligned pair of binoculars...