As an experiment I have attached a Laser to InMoov's Left eye & Wii-Camera to its Right eye.

What InMoov sees is the reflected Laser light (depicted as the white dot on the green bar)

The reason it works is because I have arranged the eyes to be a fraction squinted, this creates an angle which can then be calculated and displayed as distance.

I have tested it to 3meter range down to 10cm.

Wii Camera specs :-

The camera sensor’s exact specifications are unpublished, but it appears to provide location data with a resolution of 1,024 ×768 pixels, more than 4 bits of dot size or light intensity, a 100 Hz refresh rate, and a 45 degree horizontal field of view.

Just have to mount it in James's skull now...... and then I will be able to scan... well that's the plan.

I think this technique should work with a normal Webcam (as the Wii-Camera) using opencv to detect the brightest point in the screen (laser spots are pretty bright so i guess its feasible).