Carving eyes into a face is always a bit fraught, but an exciting time: when the eye goes in, the squirrel 'wakes up'!
It's very important to establish the overall protruding form of the squirrel's eye before setting in the eyelids. In placing the iris, I've copied Gino's drawing which, to me, gives the squirrel a sort of whimsical-but-perhaps-a-little-sinister, knowing look. Feel free to have the eye look elsewhere...