Carson Optical Binoculars - Manual (Page 7)

Others will not have a center focus wheel, and you must turn each eyepiece independently to focus.
Never try and force an eyepiece if it was not designed to turn. This may seriously damage your binocular.
Roll-Down Eyecups
Your binoculars may be fitted with rubber eyecups designed to exclude extraneous light. If you wear
eyeglasses, you may be able to roll-down the eyecups. Some binoculars are outfitted with twisting
eyecups which raise and lower the eyecups. For eyeglass wearers, lowering or rolling down the eyecups
will bring your eyes closer to the binocular lenses, thus providing an improved field of view. Please note
that not all binoculars are equipped with roll-down or twisting eyecups.
Operation of Zoom Binoculars
Many binoculars are equipped with a zoom function to allow you to take
a closer look at the object you are viewing. In order to operate a zoom
binocular, you must first focus on a distant object. To zoom in, simply
adjust the zoom lever or switch to the desired magnification setting.
Please note that you may need to adjust the center focus wheel slightly
when changing the power setting.
CAUTION: VIEWING THE SUN CAN CAUSE PERMANENT EYE DAMAGE.
DO NOT VIEW THE SUN WITH THIS BINOCULAR OR EVEN WITH THE NAKED EYE.