There is a little room at the University of Wisconsin-Madison that is filled with the eyeballs of animals — everything from the duck-billed platypus to the two-toed sloth to the boa constrictor.
"We think we're the largest collection of animal eyeballs," says Dick Dubielzig, who founded the Comparative Ocular Pathology Laboratory of Wisconsin in 1983, but he admits that this is hard to prove. "Maybe we should go to the Guinness people and see if they have an answer to that."
If there's a bigger collection out there, though, he has never heard of it. And every day, the mail brings about 20 more specimens to the lab. "About two-thirds of what we get are globes," Dubielzig says. "That means the whole eyeball."
The collection now has more than 56,000 eye specimens. Most are from dogs, cats and horses — sent in by vets who wanted help diagnosing eye disease. But the lab also has about 6,000 specimens from more exotic species.
A few days ago, for example, a couple of okapi eyes showed up, courtesy of the Bronx Zoo in New York. Dubielzig says it was the first time the lab had gotten eyes from this strange-looking relative of the giraffe.
"We pretty much have any kind of an animal you can think of — any kind of a mammal you could think of," he says.
Pathologist Gillian Shaw put on gloves and picked up one of the okapi eyeballs, which looked like a wet, gray hunk of ragged flesh about the size of a golf ball.
"I think this animal had sudden blindness or something, yeah?" she asked a colleague, who consulted the submission form that came with the eyes. Shaw then used a razor blade to slice the top off the eyeball, so she could peer down at the vitreous, a gel-like substance that helps the eye maintain a round shape, and the lens.
"I don't see anything grossly wrong, or obviously wrong," Shaw mused, "though I admit this is the first okapi eye I have seen myself."
When eyeballs like these arrive, she and her colleagues take photos and embed the eye in paraffin wax to preserve it.
Preserved samples fill blue boxes that are stacked up against the walls of this lab, and thin sections of eyeballs are put on the microscope slides that fill cabinet drawers. It's all carefully organized. So if you're a scientist who wants to study the architecture of the eye — or eye disease or anything eye-related — this is the place for you.
"This is a resource that's unlike anything else in the world. It's a one of a kind," says Ivan Schwab, an ophthalmologist at the University of California, Davis, and the author of a book called Evolution's Witness: How Eyes Evolved.
"It's the Taj Mahal of ocular specimens," Schwab says.
And the collection even has a very special human eye. One of the reasons Dubielzig got so interested in eyes is that one of his own gave him very poor vision, starting in childhood. It turned out he had an exceedingly rare eye disease, and his eye was later surgically removed — he added it to Wisconsin collection.
"What I say is that you're not really an eye pathologist unless you have your own eye in your eye collection," Dubielzig jokes.
Sometimes researchers ask the lab to help them figure out whether a species even has an eye and, if so, where it is.
"We tried to find the blue glaucus eye," recalls Shaw, with a laugh. "We were not successful finding the blue glaucus eye. It's a strange little rubbery thing, from the ocean."
Leandro Teixeira, the lab's current director, says he has been collaborating with colleagues who have been studying the effect of the Zika virus on the developing eyes of laboratory animals.
He opens up a small black case to show off teeny tiny eyes from dragonflies, spiders and a squid. Then he pulls out some plastic bags filled with fluid and the big gray eyes of elephant seals. "So these are very large eyes," he notes.
But he would like to get specimens that are even bigger. Teixeira says that a colleague recently told him that he had somehow gotten ahold of a well-preserved eye from a blue whale. "I'm excited about that eye," says Teixeira.
The one Dubielzig really wants is an eye from a giant squid, which has the biggest eye of any living animal — it's the size of a dinner plate.
"But there are no intact specimens of giant squid eyes, only rotten specimens that have been beached," he says.
He also needs eyes from the echidna, or spiny anteater, and some of the bigger whales. So if you've got any, you know where to send them.
LULU GARCIA-NAVARRO, HOST:
In a little room at the University of Wisconsin-Madison, there's a scientific collection like no other, a room full of animal eyeballs. Want to see an eyeball from a duck-billed platypus - and who doesn't? Let's face it - or a two-toed sloth? This lab has it all. And, as NPR's Nell Greenfieldboyce reports, these eyeballs give us a look into the anatomy of the eye.
NELL GREENFIELDBOYCE, BYLINE: Opening the mail can be pretty fun at the Comparative Ocular Pathology Laboratory of Wisconsin.
DICK DUBIELZIG: It's just like Christmas, yeah.
GREENFIELDBOYCE: Dick Dubielzig founded this lab back in the 1980s. He says they get about 20 deliveries a day.
DUBIELZIG: So about two thirds of what we get are globes. That means the whole eyeball.
GREENFIELDBOYCE: The day I visited, he and his colleagues had just opened up a box that contained globes from okapi. That's a relative of the giraffe, which has zebra stripes on its legs. Dubielzig says, this is a real prize because it's a species they didn't already have.
DUBIELZIG: Which is unusual - we pretty much have any kind of animal you can think of, any kind of a mammal you can think of.
GREENFIELDBOYCE: They've got more than 56,000 specimens. Most are from dogs, cats and horses - sent in by vets who want help in diagnosing eye disease.
DUBIELZIG: We think we're the largest collection of animal eyeballs. Maybe we should go to the Guinness people and see...
DUBIELZIG: ...If they have an answer to that.
GREENFIELDBOYCE: The collection includes about 6,000 eyes from exotic animals, such as those newly arrived okapi eyeballs from the Bronx Zoo. Pathologist Gillian Shaw puts on gloves and picks one up. It's a wet, gray hunk of ragged flesh about the size of a golf ball.
GILLIAN SHAW: I think this animal had sudden blindness or something.
UNIDENTIFIED MAN: Sudden blindness, yeah.
GREENFIELDBOYCE: She uses a razor blade to slice the top off the eyeball so she can peer down at the vitreous jelly in the lens.
SHAW: I don't...
UNIDENTIFIED MAN: Probably some (inaudible)
SHAW: ...See anything grossly wrong or obviously wrong, though I admit this is the first okapi I have seen myself.
GREENFIELDBOYCE: She says they'll run tests, take photos and embed the eye in paraffin wax to preserve it. Preserved samples fill blue boxes that are stacked up against the walls. It's all carefully organized. So if you're a scientist who wants to study the architecture of the eye or eye disease or anything eye-related, this is the place for you. Leandro Teixeira pulls out a small black case filled with teeny tiny eyes.
LEANDRO TEIXEIRA: Here's the list of - so a nautilus, dragonfly, jumping spider, a cockeyed squid.
GREENFIELDBOYCE: Then he pulls out some plastic bags filled with fluid and the big gray eyes of elephant seals.
TEIXEIRA: So these are very large eyes.
GREENFIELDBOYCE: And the collection even has a very special human eye. Dick Dubielzig says one of the reasons he got interested in eyes is that one of his eyes had very poor vision since childhood. Eventually, his eye had to be surgically removed, and he added it to the rest.
DUBIELZIG: What I say is that you're not really an eye pathologist unless you have your own eye in your eye collection.
GREENFIELDBOYCE: Now, there are other animal eyeball collections out there. But ophthalmologist Ivan Schwab of the University of California, Davis says this one eclipses them all.
IVAN SCHWAB: This is a resource that's unlike anything else in the world. It's a one of a kind.
GREENFIELDBOYCE: He wrote a book about the evolution of eyes, and he used this lab a lot.
SCHWAB: It's the Taj Mahal of ocular specimens.
GREENFIELDBOYCE: Still, it doesn't have everything. What eye would Dick Dubielzig love to get?
DUBIELZIG: I usually answer that question by saying the giant squid, which is the biggest eye of any animal.
GREENFIELDBOYCE: Its eye is the size of a dinner plate. He also needs eyes from the spiny anteater and some of the bigger whales. So if you've got any, you know where to send them. Nell Greenfieldboyce, NPR News. Transcript provided by NPR, Copyright NPR.