Creating blinking eyes using expressions

Hi Guys,

First of all, as this is my first post, let me just say that this community is a great resource for After Effects!

That being said, here's my question:

I'd like to create random eye blinking using an expression that scales the Y scale down to 0 and back up again over a given period of time with random intervals.

I've seen several posts doing this with just opacity, but I'd like to do it with scaling.

I can't seem to figure out how to do this...

Any help would be much appreciated.

Thanks,
Allard

Hi Ben,

That's exactly what I was looking for,
Thanks for pointing me in the right direction!

Cheers,
Allard