I have had trouble with eyes for years, always looked like Marty Feldman. Then one of the guys posted this video.

www.youtube.com/watch

Not sure if it will work with the pencil, but it certainly solved my problem.

Best and simplest advice I can give you is to paint the eyes first. If they're oversize no big deal just paint the edges with the same paint you're using for the face to narrow them down. If you don't like it paint over them with the flesh paint and redo them.

For years I'd finish the face and then mess up the eyes and have to redo the whole darn thing, wish someone had told me this sooner.

Just remember, take a look at photos of guys in the positions you're modeling.  Do you EVER see whites in their eyes?

You have the right idea about trying a pencil, it gives you better control than a wet brush, but at his scale, even the sharpest of pencils though, can leave you with clean up work.

If the sculpt  has the eyes recessed, or has  prominent eyelids, or if the figure is squinting, the lead point is likely still drawing over  areas you don't want it to:

1.)  Centered iris,  but is past the eye shape - I over exaggerated the blue circle a bit just to illustrate this.

2.)  Just paint over the excess (pointed out by arrows)  with your skin tone of choice.  Note too, I've raised the blue iris, so that the lower end just touches, or is slightly covered by the bottom eye lid.

3.)  The eye cleaned up.  Now, if you want to go further, can add the black pupil, a white highlight, etc...

regards,

Jack

A toothpick makes a very good substitute for a very fine brush.  Shake a bottle of paint, remove the top and lay it down upside down, so there is a layer of paint in the liner.  This is just the right amount of paint to put on the tip of the paintbrush.  Now, it is not very much paint, so you need to be re-dipping frequently, but this gives you good control, no sudden big blob flowing out where you do not want it to go.

jack, do you use standard white or an off white.

Bish - I mix an off white by adding a drop of blue and a brown, or even a dark flesh tone.  Aim is for something in middle range between white and the flesh tone, having a dull blue to purple hue.

Don -  another good suggestion with the toothpick. 

I find though with acrylics there is little leeway with using a small drop of paint on the end of a sharp toothpick and how quickly it dries before you have time to apply it.  Again, there is the likely chance some clean up will be required as the iris is rarely round, unless your figure is intended to convey a look of shock, surprise, etc.

regards,

Jack

Cheers, I recall reading something about using an off white.

Hmm;

   I was once told that in 1/35 just darken the center of the eye, because if you tried to show the whites your figure would look " Bug Eyed " .Do I need to be corrected here ?     T.B.

tankerbuilder -   the bug eyed look results from having completely round dots.  If they are too large for the face, and adding surrounding white, just amplifies it that much more.

Yes some don't bother with the whites, and just leave it a flesh tone.  It's a step to add little extra to the figure, like I did with mine here:

regards,

Jack