I see double image unless I take the lens as close as the binoculars can go

Thats how binoculars are. Yours in this case is really strong. the closer you are to something, looking at it, the more magiflyed you going to be. try view things far a distance, really far away. no more double right?
Everything you need to know to become an expert:
on this website: http://www.chuckhawks.com/binocular_basics.htm
It is surprising how many people do not know how to focus binoculars correctly. There are two common focusing systems used in binoculars.
The first is individual eyepiece focus. This system is simple to understand, and easy to manufacture. It also lends itself well to sealed optical tubes, and thus is usually the focusing system used for waterproof binoculars. Individual eyepiece focus means that to focus the binoculars to your eyes, you simply focus the left eyepiece to your left eye and the right eyepiece to your right eye. There is no centrally located focusing mechanism. It is done like this. Look at something in the distance. Close the right eye (or cover the front of the right binocular), and focus the left eyepiece to your left eye. Close the left eye (or cover the front of the left binocular), and focus the right eyepiece to your right eye. You are finished, until you need to look at something at a different distance, in which case you need to repeat the process.
Because individual eyepiece focus is time-consuming, center focus is more common. Unfortunately, very few people understand how to correctly use center focus binoculars. Here is how it is done. Aim your binoculars at something in the distance. Close the right eye (or cover the front of the right tube), and focus the left side of the binocular to your left eye using the center focus control, which is concentric with the pivot shaft between the binoculars. (Note: the left eyepiece itself does not focus on center focus binoculars.) Next, close your left eye (or cover the front of the left tube), and focus the right eyepiece to your right eye. DO NOT touch the center focus control while you are focusing the right eyepiece to your right eye. Now you are finished. What you have just done is adjust the binoculars for your individual eyes. (Practically everybody's left and right eyes are different.) From now on, you only need to adjust the center focus control when you look at things at different distances. Center focus is faster and easier to use than individual eyepiece focus, once you have initially set the binoculars for your eyes.
Binoculars are commonly described by using a pair of numbers, as in "7x50" or "8x25." The first of these numbers refers to the magnification offered by the binocular. Magnification is why most people buy a pair of binoculars. In the examples above, "7x" means the binocular makes whatever you look at appear seven times closer than it does to the unaided human eye. "8x" means the binocular makes whatever you look at eight times closer than the unaided human eye. "10x" makes things look ten times closer, and so on. The first number used to describe binoculars always refers to their magnification. Common binocular magnifications are 6x, 7x, 8x, 9x, and 10x.
There are also variable power (zoom) binoculars, such as 7-21x50. These almost always perform much better at the low power setting than they do at the higher settings. This is natural, since the front objective cannot enlarge to let in more light as the power is increased, so the view gets dimmer. At 7x, the 50mm front objective provides a 7.1mm exit pupil, but at 21x, the same front objective provides only a 2.38mm exit pupil. Also, the optical quality of a zoom binocular at any given power is inferior to that of a fixed power binocular of that power. In general, zoom binoculars are not the bargain they seem to be.
Remember that everything (including movement) is magnified when you look through a pair of binoculars, especially your own shakes and tremors. So the higher the power, the harder it seems to hold the binoculars steady. 6, 7, or 8 power binoculars are easier for most people, even those with very steady hands, to hold reasonably still. The higher powers sound like a good deal, but often result in jiggly, blurred views. This is why 7x binoculars are chosen by so many experts, including the military.
Power affects brightness. Other things being equal, the higher the power, the dimmer the view. And power also affects the field of view of the binoculars. Again, everything being equal, the higher the power, the smaller the field of view. So, as you can see, power must be balanced against other desirable characteristics when choosing binoculars.