from The Century Dictionary and Cyclopedia
- n. A genus of cyprinodont fishes unique among vertebrates on account of the division of the cornea into upper and lower halves by a dark horizontal stripe of the conjunctiva, and the development of two pupils to each orbit, so that the fish appears to have four eyes, one pair looking upward and the other pair sidewise.
Sorry, no etymologies found.
A membraneous fold, enclosing the bulb of the eye, stretches across the pupil, dividing the visual apparatus into the upper and lower half; a curious formation, suited to the peculiar habits of the anableps.
We see the barreleye fish, whose eyes extend from its head on tubes, Anableps anableps, a fish with four eyes, and the mantis fish whose color vision is so acute, Dr. Knowlton writes, that it makes what we see look like it is "practically in black and white."