question stereo with augmented reality

[Darkmax]

thx it works with two individual cameras, but when i tried with the glasses it only has one usb cable for the two cameras and it shows only the first added camera but the program detects both cameras because on the interactive window show this:

artoolkit.dle            	ARToolkit Extension
VideoCamera.dle          	Video Camera Extension
** NOTIFY: Connected to 'Vimicro USB2.0 UVC PC Camera' (640 x 480 , 30.00 fps)
** NOTIFY: Connected to 'Vimicro USB2.0 UVC PC Camera' (640 x 480 , 30.00 fps)
Loading File: vcc_male.cfg
** Load Time: 1.01 seconds

And on my left eye i can see the image but on the right i see only black

I don't know if there is a way to resolve this.