Just because I couldn’t find the pattern again to make eyes I made up my own.

As an aside – I am starting (jokingly) a cottage industry of froggie hats. I have finished 2 and have plans for AT LEAST 2-3 more

Eye Pattern:
Cast on 14 sitches in the base color of the hat on to needles 1-2 sizes smaller than the ones used for making the hat. Leave an extra long tail

Knit in Stockinette for 6 rows
Row 7 Knit 5 knit 2 tog. (twice to get to 12 stiches)
Row 8 Switch to white (leaving a long base color tail) and knit 2 tog for whole row
Row 9 knit 2 tog again

Leaving a long tail draw through remaining 3 sitches. Sew up side with white and base color tail in turn.

Sew on black pupils as desired

Stuff tails into eye to give it body

Weave beginning extra long tail through bottom 14 stiches and draw tight to make the eye into a roung ball. Use tail attached eye to hat.