The Barrel Eye Fish

The barrel eye fish in the photo has a transparent skull, through which its green eyes see.

In the photo you can see eyes looking out from inside its transparent head. The things in front are not eyes but are similar to our nostrils. Its eyes are shaped like barrels (binocular-shaped, if you prefer) and thus its name. Spherical eyes are not as well adapted for the dark deeps in which it has to survive. Its eyes swivel. They can look forward, or rotate to see backward through the top rear of its cranium. Here is one link at Monterey Bay Aquarium Institute. Here is another at YouTube.