In many countries you can buy inexpensive eyeglasses and contact lenses without a prescription. That's not the case in the United States. In 2016 the American Optometric Association (AOA) spent $1.8 million lobbying and another $1.4 million in campaign contributions to ensure corrective lenses are expensive for Americans, and therefore highly profitable. Yascha Mounk, a contributing writer at The Atlantic, writes in his article, "The Great American Eye-Exam Scam:"

When I last went to an eye exam at a storefront optician in the United States, for example, the staff gave me the hard sell on glasses that would have cost hundreds of dollars, as well as on contact lenses that were much more expensive than identical ones sold by online retailers. Thankfully, I knew that two laws, one passed in 1997 and the other in 2003—which had, incidentally, been loudly opposed by the AOA—gave me the right to demand a copy of my prescription. I stood firm, and later went online to order perfectly fine glasses and contact lenses at a fraction of the price. But how many customers give in to heavy-handed sales tactics?

After reading this article, I ordered one of these vision checkers for $35, so I can test my vision and order eyeglasses online for a fraction of what it costs at a brick and mortar store.

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Approximately 14 percent of the world's population suffer from dry eye disease (DED) but treatments are limited because it's difficult to model the complex human eye for drug development. Now though, University of Pennsylvania bioengineers developed an "eye-on-a-chip" complete with a motorized blinking eyelid. The hope is that the artificial eye will lead to a deeper understanding of dry eye disease, enable drug screening, and even become a testbed for contact lens technology and eye surgery. Their technology also received the 2018 Lush Prize awarded for innovations that could help eliminate animal testing for shampoos and other beauty product. From Eurekalert:

In this study, (Dan) Huh and (Jeongyun) Seo focused on engineering an eye model that could imitate a healthy eye and an eye with DED, allowing them to test an experimental drug without risk of human harm.

To construct their eye-on-a-chip, Huh's team starts with a porous scaffold engineered with 3D printing, about the size of a dime and the shape of a contact lens, on which they grow human eye cells. The cells of the cornea grow on the inner circle of scaffolding, dyed yellow, and the cells of the conjunctiva, the specialized tissue covering the white part of human eyes, grow on the surrounding red circle. A slab of gelatin acts as the eyelid, mechanically sliding over the eye at the same rate as human blinking. Fed by a tear duct, dyed blue, the eyelid spreads artificial tear secretions over the eye to form what is called a tear film.

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"Ocular dominance" is defined as "the priority of one eye over the other as regards preference of use or acuity of vision." Awareness of your dominant eye is important for photography, golf, baseball, and archery. The above video explains how to conduct the Miles test to determine your dominant eye.

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Chinese nanotechnologists injected tiny particles into the eyes of mice resulting in the rodents demonstrating "infrared 'night vision'" that lasted for months. According to nanoscientist Tian Xue and colleagues the University of Science and Technology of China, the technology could eventually help those with certain kinds of color blindness and "provide the potential for close integration within the human body to extend the visual spectrum." From New Scientist:

Like humans, mice cannot perceive light with a wavelength longer than 700 nanometres, which is at the red end of the visible spectrum. But the nanoparticles absorb light with longer – infrared – wavelengths and convert it into shorter wave light that retinal cells can detect. This converted light peaks at a wavelength of 535 nanometres, so the mice see infrared light as green...

Some mice did develop cloudy corneas after the injection, but this disappeared within a fortnight and occurred at similar rates to those in the control group. The team found no other evidence of damage to the mice’s eyes two months after the experiment.

The researchers published their findings in the scientific journal Cell: "Mammalian Near-Infrared Image Vision through Injectable and Self-Powered Retinal Nanoantennae" Read the rest

And if shaking your head really fast is, er, problematic, you can also just look at an angle or move away from the screen until the image appears.

Here's an Instructable on how to make your own head-shaking illusions.

(via r/interestingasfuck)

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Researchers have spent decades exploring methods to 3D print organs for transplant but progress is slow due to the complex structure of, say, a kidney or pancreas. Precise Bio, a startup founded by scientists from Wake Forest Institute for Regenerative Medicine, claim that the first real success will come from 3D-printed corneas. They've already conducted animal studies and are building a roadmap toward human trials. From IEEE Spectrum:

Corneas could be the first mainstream application of bioprinting, (Precise Bio CEO Aryeh) Batt says, in part because they have a layered structure that’s a good match for the technology. Each layer consists of different types of cells and fibers, which the printer could lay down in sequence, and these layers don’t contain blood vessels or nerves. What’s more, putting a new kind of transplant in the eye is inherently safer than implanting one deep in the body, since physicians could easily check for signs of trouble and could remove the tissue if anything seemed wrong.

There’s certainly a need for more corneas in the world, says Kevin Corcoran, president and CEO of the Eye Bank Association of America. In 2017, his members supplied nearly 51,000 transplantable corneas to patients in the United States, and also sent more than 26,000 abroad. Internationally, “there is a tremendous amount of unmet demand,” he says. “It’s estimated that 10 million people suffer from corneal blindness globally, primarily because they lack access to effective and affordable treatment.”

Part of Precise Bio’s proprietary approach is its printer, which uses a technique called laser-induced forward transfer to propel droplets of bioinks onto a surface.

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What animals have night vision and how the hell can they see in the dark anyway? (Nat Geo WILD via The Kid Should See This)

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If you've ever tried to buy online eyeglasses, you'll understand why this $1.99 ruler from Eyeque is a godsend. They also sell a $29.99 kit to check your vision using your smartphone.

The simple to use EyeQue PD ruler provides you the ability to measure pupillary distance. Pupillary distance (PD) is the distance measured in millimeters between the centers of the pupils of the eyes. The PD is required to order eyeglasses.

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Based on a recent eye-tracking study, researchers believe there's a genetic component to variations in how humans process visual information. Read the rest

Invisible London is a great primer on infrared filmmaking, with lovely shots of London as the backdrop. Read the rest

A Snellen chart (below) may just look like random letters in different sizes, but they were carefully designed to measure visual acuity. This piece on testing the limits of human vision brings it all into focus. Read the rest

Look at the above image. The higher the peaks, the more sensitive your eyes are to contrasts at those frequencies. Ian Goodfellow spotted the image in a scientific paper about spatial frequency analysis and brilliantly observed that "It's like a graph that is made by perceiving the graph itself." Over at Mind Hacks, Tom Stafford explains the science of spatial frequency, the same concept behind the classic "Marilyn Einstein" image below that was created by Aude Oliva in 2007. From Mind Hacks:

Spatial frequency means how often things change in space. High spatial frequency changes means lots of small detail. Spatial frequency is surprisingly important to our visual system – lots of basic features of the visual world, like orientation or motion, are processed first according to which spatial frequency the information is available at...

Spatial frequency is also why, when you’re flying over the ocean, you can see waves which appear not to move. Although your vision is sensitive enough to see the wave, the motion sensitive part of your visual system isn’t as good at the fine spatial frequencies – which creates a natural illusion of static waves.

See Einstein below? Now go a few steps back from your screen and look again:

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DEVO's Mark Mothersbaugh has a line of fantastic spectacles for booji boys and girls. Guaranteed to help you stay focused on the smart patrol! Here's Mothersbaugh on how eyeglasses improved his vision, and his life:

I have a really bad astigmatism and extreme myopia. I could see just enough to make it around a room but kids would throw a ball, and it would hit me in the head. I was happy and just kept running around because I didn’t know that I was any different than anybody else. The teachers at school would ask me to read the board and I’d say, ‘What’s a board?’” and they’d put me in the corner. Finally they tested me, and it was like “Oh my God, he can’t see the big ‘E’ on an eye chart from 12 inches away.

So, I got glasses right before my eighth birthday, and in the car on the way home I remember seeing clouds and trees. I had never seen what the top of a tree looked like. I had never seen a roof of a house. I was stunned and excited. The next day, I was drawing pictures. I remember the teacher who had been totally frustrated with me and disciplining me every day said, “Mark, you draw trees better than me.” That was the first time a teacher had ever said anything nice. I was struck by it, because I had never had a teacher say anything positive to me in my life. And I remember that that night, I went home and had a dream that I was going to be an artist.

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"If only you could see what I've seen with your eyes."

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Turns out that long stints in outer space affect levels of cerebrospinal fluid. That explains why many astronauts who had 20/20 vision before space missions needed glasses upon return, according to a paper presented this week. Read the rest

A series of recent, influential design books and articles have convinced the web's designers to go for grey-on-white type, despite the fact that many people can't read low-contrast type (and it's even worse on mobile devices, which are often read in very bright sun, on screens that have been dimmed to save battery) Read the rest

Tommy Edison, the very funny "Blind Film Critic," who has been without sight since birth, answers the question: "Does it bother you that you don't know what you look like?"

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