The eyes

This part is not covered in the video tutorial, hence I found one tutorial of eyes modelling and rigging on the internet. Start with drawing a sphere as an eyeball and convert it to Editable poly, under the polygon mode select the two layers of polygons as shown below to bring them forward to give some depth. Select one more layer of the polygon and rotate them as a part with holding down the shift button to colon the inner part of the pupil. Make sure the pivot is always at the centre.

 

Connect the edges to create another layer of polygon, and pull this layer out forward to give some more depth. Hide the outer part and created another sphere, scale it until it looks like the shape shown below to mimic the part inside the pupil.  

Apply the Raytrace material onto the eyeball, so that it appears bright and shines enough like a real eyeball. As is the same, apply the pupil bitmap material onto the pupil. And finally I got the eyes as follows:

Rig the eyes:

In order to activate the eyes--- enable to move around, I start to rig the eyes by group the eye as a whole first, and then create a dummy under the helper panel, make sure the pivot is always at the centre to the object here, as it is very important that the pupil moves together with the eye ball after rigging. 

 

Go to the animation panel and choose look at constraint to connect it onto the dummy.

 

Afterwards, click Lookat Constraint under the motion panel and tick the Keep Initial Offset, so that the pupil will follow the movement of the dummy.