Look straight forward with your left eye closed, and stretch your right arm out to the right side. Bend your fingers forwards, and wave with them, while you move your arm forwards. At a certain point you will see your fingertips. This is the temporal border of your visual field for the right eye, about 90 degrees.
Now, close your right eye, and look at the same fingers with your left eye. You must move your right arm considerably more forward in order to see your fingertips. This is the nasal border of your visual field for your left eye, about 60 degrees.
In order to get a visual understanding of the visual fields, the borders are projected flat on a chart:
As you can see, the fields are drawn just as you see them - right field on the right side, left field on the left side. On the temporal sides the borders are at 90 degrees (each step 15 degrees). On the nasal, upper and lower sides about 60 degrees.