I got some 9mm "Jay" eyes for my "wife" worm:
I've not hollowed out her eyes/head yet, but they look like a good fit.
With the kids I think you're looking at needing 5mm eyes. Problem there is that I can only find them in single colours with black pupils - I think you really need two colours and the pupil for them to look right.
Partly because of that reason, and partly because I want the kids eyes' to be a genetic combination of the dad's orange/yellow eyes and mum's blue/yellow eyes, I've gone with just painting the eyes.
I've given the kids all the same basic body colour as dad has (and mum will have), but their coloured skin sections are a mixture of dad's dark blue skin and mum's autumn red/orange/brown skin (or at least, that's the colour I will be painting her once her glass eyes are installed), or shades of one of the parents colours. I'm trying to go for skin and eye colours that would actually be feasible in the offspring of mum and dad.
Here's where I'm at just now - fully painted and awaiting hair (I've drilled holes in them for the hair to insert into since taking these pics):
Looking forward to seeing what colour schemes other people come up with. :thumbsup