Visit a medical laboratory to see how artificial eyeballs are made. Every single eye is made by hand and precisely tailored to its wearer.
", "is_us_only": "false", "title": "I Didn't Know That: Making an Artificial Eye", "url": "http://video.nationalgeographic.com/video/science/weird-science-sci/idkt-artificial-eye/", "country_code_deny_list": [], "allowUserEmbed": "True", "related": { "link": [ { "url": "http://science.nationalgeographic.com/science/", "name": "More About Science" } ] }, "credit": "National Geographic", "smil": "http://video.nationalgeographic.com/video/player/data/xml/idkt-artificial-eye.smil", "country_code_allow_list": [], "HTML5src": "/video/player/media-mp4/idkt-artificial-eye/mp4/variant-playlist.m3u8", "still": "http://video.nationalgeographic.com/exposure/core_media/ngphoto/image/63375_0_616x346.jpg", "transcript": "JONNY PHILLIPS:
Did you know that the average human eyeball is two and a half centimeters wide, by two and a half centimeters deep, by a fraction over two centimeters tall.\u00a0 Now that's not the kind of information you're gonna need every day, unless of course, you make them for a living.
NARRATOR:
This medical laboratory has been producing artificial eyes since World War 1.\u00a0 Back then, they were known as the army spectacle depot, but they've come a long way since then.\u00a0 Now they look after over 40,000 patients and they make over 6,000 eyes a year.
Every single eye is made by hand to an exact order.\u00a0 A wax pattern of the patient's eye socket is sent here to the lab in Blackpool and a plaster of Paris cast is made.\u00a0 This produces a mould that is the exact shape of the eye that they're going to manufacture.
The iris --\u00a0 or coloured part of the eye -- is painted onto a flat plastic disc which is measured to the size of the patient's remaining Iris.\u00a0 Each Iris is hand-painted using oil-based paints and the technicians work from either a digital photo or a previously painted eye to make sure that it will match the other eye.
After 18 hours, the Iris paint is dry and it gets pressed into a button-shaped disc.\u00a0 This puts a curve on top of the Iris so that it will be flush on top of the round eye.
The Iris is placed upside down in a mould and the white of the eye is made.\u00a0 It's made out of polymethyl methacrylate; a medical grade acrylic plastic similar to the material that's used to make false teeth.
Once prepared, it's squashed down into the cast of the top of Iris, and the whole mould goes into an oven for two and a half hours. The eye is now starting to take shape.\u00a0 The excess acrylic material is trimmed away on a grinding wheel and the eye gets stained and veined.
The average human eye isn't snow white, so a bit of watercolour paint is dabbed around the edges depending on the patient's natural colour.
This embroidery silk is used to replicate the veins of the eye.\u00a0 The thread is separated into individual fibres and applied with an acrylic varnish.\u00a0 Just 1 centimeter of this thread will provide enough fibres to make over 100 eyes.
A coat of clear acrylic varnish is applied over the top of the eye and It gets oven cured to seal it.\u00a0 Finally, a buff and polish gives it a nice glossy finish and the appearance of a living eye.
The expected lifespan of an artificial eye is around 6 years, as long as it gets looked after properly.\u00a0 And the end result is pretty amazing.\u00a0 Meet Pavel, he's been wearing an artificial eye since an accident when he was 15.\u00a0 Can you tell which one it is?\u00a0 Are you looking hard?\u00a0 No I can't tell either. Ok, it's actually the one on the right of the frame.\u00a0 Thanks Pav.
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