This is done in two parts. First set the two barrels of the binoculars to the correct distance and then set the focus for each eye.

To set the binoculars barrels to the correct distance, move the two barrels closer together or further apart until you can see through both eyepieces comfortably and the image appears as one.

To focus your binoculars for your eyes:

• close your right eye and look at a distant object through your binoculars with your left eye.
• adjust the centre focusing wheel until the image comes into focus. Your eye will try to adjust as well, so look away, wait a few seconds until it relaxes and look back again and repeat to re-adjust the focus.
• Then leave the centre focus wheel untouched to adjust for your right eye.
• Now close your left eye and adjust the dioptre correction (where it shows + and -) until the image becomes sharp.
• Once this is done you should not have to touch the dioptre adjustment again as all the focusing will now be done using the centre wheel for both eyes.