Eyes are our windows to the world, but they also double as the world's windows to us. Part 2 of MNN's guide to human eyes looks in from the outside, covering everything from iris color and eyewear to the myriad ways our eyes communicate and convey emotion. And if you missed it, make sure to check out Part 1, which examines how an eyeball turns reflected light into the rich, wide-ranging imagery we see in our minds.

human eye infographic part 2

Previous: Part 1 of Mother Nature's Pop Science Guide to the Human Eye

More of Mother Nature's Pop Science Guides: