A knitted eyelet is essentially an increase paired with a decrease, and makes a hole about the height and width of one stitch. But you can do more with the eyelet than a single hole. How about a double eyelet?
You see double eyelets on their own, but also combined is some kinds of lace.
K2tog, yarn over, yarn over again, ssk. On the next row, purl 1, knit 1 into the two yarn overs.
Ssk, yarn over, yarn over again, k2tog. On the next row, purl 1, knit 1 into the two yarn overs.
You can have a little fun with the visible movement of the stitches in Version 1.
For example, try arrange double eyelets in a diamond. You'll see this in the Peacock's Tail and the Picot Eyelet Diamond from the first Walker Treasury.
The free Botanical Cowl pattern uses a simple stitch pattern of double eyelets.