The numbers on binoculars indicate the magnification power and the size of the objective lens in millimeters. The first number in the pair refers to the magnification power, which tells you how many times closer the image you see through the binoculars will be compared to what you would see with the naked eye. For example, if the binoculars are labeled 8x42, the image you see through them will be eight times closer than what you would see with the naked eye. The second number in the pair refers to the size of the objective lens in millimeters, which affects how much light can enter the binoculars. The bigger the ratio of the two numbers, the sharper and brighter the image. For example, 8x42 binoculars provide a brighter, sharper image than 8x32 or 10x42 binoculars. Additionally, some binoculars may have a third number that represents the field of view, which is the area you can see out to 1,000 yards when looking through the binoculars. Fields of view are usually expressed in feet, but theyre sometimes shown as angles.