Andrew Huberman· PhD
and so this trigeminal nerve becomes inflamed or in other ways is hyper activated in some cases and that causes the Deep pain below the eye because it is that first branch of the trigeminal nerve which is the ophthalmic branch which tends to be activated first so people start feeling as if there's a pain behind their eye in particular on one side oftentimes there's lacrimation which is tearing up there can be some nasal discharge