Following Eyes

Ive built the eyes with a few servos and done the coding for blinking which is great
I want to make them be able to follow the person or motion to make this much more realistic. I only found 1 example for far with a sensoor not suit due to the sensor too bif for inside the eye and i dont want it in the middle of the faces forehead

What sensor will you use to track "person or motion" ?

Do you have links to the sensor that is too big? That might help us understand what your goal is.