At first glance, your lens for your right eye and the one for your left eye look exactly the same. So you might wonder why you need a specific lens for each eye. Couldn't you swap them?
One look at your prescription will show you that this is not possible. After all, your eyes do not have the same correction.
The answer to this question is of course no, you can't switch lenses.
If the wrong lens is in your eye, you will notice very quickly that your vision will be blurry and/or unclear. If you are in doubt because your correction is very weak in both eyes, nothing could be easier. Cover one eye with your hand and check whether or not you can see well.
if you are in any doubt, you should consult your trusted optician. They will be able to help you decide which contact lens is right for which eye.