From the website:
The inside of your eye is one thing you’re guaranteed never to get a good look at. Even if you could, the pupil is far too small an aperture to allow you to see the entire interior. University of Michigan ophthalmologic photographer Richard Hackel compares the problem to taking a picture of a room through a keyhole. To overcome this hurdle, Hackel uses a computer program to stitch together images taken from 20 different angles by a special digital camera. The result is an unusual, fully detailed map of the inside of a healthy 26-year-old’s eye.
Larger pic (very interesting): Link - via reddit