1- This is what a human eye looks like after a keratoprosthesis, which is a surgical procedure in which a diseased cornea is replaced with an artificial cornea.
2- It's a herd of zebras, but at first glance the photo reflects their shadows. If you zoom in or out, you'll see the zebras.
3- Glass frogs (Centrolenidae) are native to and distributed throughout South and Central America. There are many examples of this type of frog with translucent skin, and experts say this evolution may be a way to avoid predators. Interestingly, they are among the 0.2% of amphibian species that have a heart visible through their skin.
4- Visual representation of the amount of copper extracted from a mine.
To create this image, photographer Dillon Marsh took a photo of the original mine, then collected data on the amount of metal collected, and developed CGI images of the metal mass in real-world proportions.