Choosing binoculars is a two-part process, based as much on what you plan to do with them as on your personal preferences. Ask yourself, 'What is my main reason for binoculars?' This main reason is the overriding criteria and will or should influence your decision.
For instance, compact binoculars fit in the palm of your hand, and are a good solution to the bulky size and heavier weights characteristic of full-size binoculars. Both are equal in terms of magnification, image quality, and price. But some people find compacts harder to adjust than full-size binoculars, and if you wear glasses, they can be difficult to align. Other than that, you can choose from among narrow-set, wide-set, and in-line styles. None is better optically than the others; the style you choose is a matter of preference.
Next you decide on what power you need. The power represents the number of times an image is magnified by the binoculars. Most common for outdoor uses like bird-watching and hunting are 8x and 10x. Higher powers like 20x and beyond are preferred by astronomers because they capture more light from the dark sky. Generally most of the while 7x is probably sufficient for sports spectators and theater-goers.
Then choose a lens size. You also need to know the diameter of the binocular front objective lenses. This number is represented in millimeters by the second number in binocular measurements (such as 8x42). Smaller number objective lenses are good for day time use. Larger lenses, say 50x or 60x and higher allow more light to enter and provide a better image, but can also be much heavier and may require a tripod to use them. The higher numbers usually are used for night vision work.
There are other new features such as Electronic circuitry giving some binoculars special capabilities. Binoculars with image stabilization use a battery-powered system you turn on and off to steady the image. When you hold binoculars up to your eyes, even the slightest shakiness in your hands causes the image to jump. As a result, you see less detail in the image.
Some manufacturers have added digital cameras to their binoculars. While it might be tempting to think you can get great pictures of that tiny bird you're seeing up close, don't be fooled. The image quality of photos taken with those cameras is low, with sharpness and color poorly reproduced. And the picture is not necessarily magnified as much as the image you're seeing through the binoculars, since the camera uses a separate lens. If a tripod or platform is not used it can be difficult to shoot sharp images.
These new 'power' eyes will be a great help for you to focus in on the important things around you in your life. The main thing in choosing binoculars is for you to be able to enjoy them for many years ahead.