Archive for the ‘Weekly Optical Illusion’ Category

Weekly Optical Illusion: “Coffee Eyes”

This optical illusion is somewhat unsettling… considering that most people (including myself) can answer “yes, I do probably drink too much coffee”. But this particular illusion has very little to do without aan occasional over indulgence in the enjoyment of a cup of Joe. This optical illusion actually has a lot more in common with the rotating snakes illusion that we featured some months back. Once again your eyes are drifting away from a point of focus and giving the appearance that the object is moving, when it’s truly your eye doing the trick.

Tuesday, May, 21 2013 by

No, You Didn’t Break His Glasses: Avoiding the Eyeglass Scam

Times must be really tough, because I’ve been seeing a lot of articles about the “broken eyeglass scam.” If you aren’t familiar with it, here’s how it works:

You are walking down the street and you collide with another pedestrian. You make your apologizes and attempt to move on, only to be accosted with the complaint that you broke the person’s glasses, which just happened to be in their pocket at the time you bumped into to him (or her).  The pedestrian will then brandish his damaged glasses so that you may see the havoc caused by your exuberant stride, and may go on at length about how he is a man of modest means and is now unable to see clearly.

Therefore, you are under obligation to pay for the repair of his glasses. Or at least contribute to the cost. $50 should do the trick, but he’ll gladly accept $20.

Keep your wallet shut.

Along with the pigeon drop and the shell trick, this is one of the oldest scams in the book. Variations on the con involve other breakable items, such as wine and medication bottles.  In any case, however, keep in mind that you aren’t under any obligation to pay up.

In most cases, all you need to do is look the scammer in the eye and say,

“Sorry, I don’t have any cash.”

or

“I’ll have to call the police so that I can file a claim with my homeowner’s insurance company.”

or

“I know this is a scam, and I’m calling the cops.”

 

In most cases, scammers will move on, looking for another target.

The scam works for two reasons: First, the victim is jarred by getting bumped into and then verbally confronted by the scammer. The second reason is that con artists prey upon the decency of others.  Nobody likes to be the cause of causing damage to another person’s property, particularly something like glasses. But the chances of glasses getting broken in a person’s pocket as a result of a street collision is pretty slim. . .don’t let confusion and having your emotions played cloud your thinking.

As I said earlier, most scammers will flee the scene if confronted. However, if the con artist is persistent and won’t leave you alone, here are some tips for dealing with the situation:

1. Move into an office building, restaurant or shop. If the con artist has been working the area, it’s likely that the employees or security guards know who he is. He won’t want to follow you into some place where he could be outed. If he hangs around outside the shop or building, call the police.

2. If the scammer menaces or threatens you (very unlikely, but possible) scream for help. He doesn’t want to attract attention and will probably run.

3. Suggest that the scammer replace his glasses at Zenni Optical, where he is sure to get a great deal.

One more thing: Even if you don’t fall for the scam, call your police department’s non-emergency line to report the incident. Police are often interested in busting street scammers and can use your information to address the problem.

 

 

Wednesday, April, 10 2013 by

Even Computers Can Be Fooled By Optical Illusions

We here at Zenni have written about optical illusions extensively (see here, here, and here). However, it’s not just humans whose eyes can play tricks on itself. Computers can be tricked too, a new study finds.

Each computer model was shown a pair of lines, one longer than the other, and each line had both an arrowhead and an arrow tail or an X at both ends. The computer model then had to guess which line was longer. Over time, the researchers were able to train the system, named HMAX, to correctly identify the longer line 90 percent of the time.

Testing like this can result in something that sounds a bit like what a mad scientist would do; as researcher Astrid Zeman told LiveScience, “If we think of this visual system as something we implant in a robot, this means that we can grow whole bunch of robots up in different environments. Then, once our robots have matured and have learnt to see things, we can then smash their brains open to see what they are thinking. This is something that we can’t quite do with humans.”

The second part of the study showed a pair of lines to the computer system, but this time the top line always had two arrow tails and the bottom always had two arrowheads. For humans, if both lines are the same length, we are duped to believe the top line looks longer. And the study showed that the computer system was also duped around 1.6 percent of the time.

With a finding like this, the researchers are able to eliminate previously believed explanation for this illusion in humans—was it our brains misinterpreting the arrowheads and arrow tails as depth cues? Or do we focus more on overall information about shapes than their elemental parts? These findings show, as LiveScience wrote, that it may result simply by how our visual system processes information that requires further elucidation.

“If we build robots with artificial brains that are modeled off our brains, the implication is that these robots would also see illusions much like we do,” Zeman added. “By imitating the amazing accuracy, flexibility, and robustness that we have in recognizing objects, we could also be copying potential errors in computation that manifest in visual illusions. … These illusions bring to light new questions about how we perceive the world and the assumptions we make about the world.”

Monday, April, 8 2013 by

What You See Isn’t Really There

Magic isn’t the result of any conjuration of supernatural feats; it’s about creating illusions that make you look like you performed a seemingly impossible or supernatural feat. What you see in front of you isn’t really there; however, knowing that simple fact doesn’t mean you won’t think otherwise.
 

 
The video above is an illusion created by the artist Brusspup using anamorphosis, a trick that takes advantage of how our brains make sense of the world by using distorted perception. By having the viewer focus on a specific vantage point, the artist is able to trick us into thinking we’re staring at a three-dimensional Rubik’s Cube. However, the moment the orientation is shifted, as Brusspup moves the paper, the illusion disappears.

When our brains are presented with contradictory images, our mind’s eyes seek to create order. While we may know that the Rubik’s Cube in the video is not a three-dimensional object, we see what makes sense. In Lawrence Wright’s book Perspective in Perspective, he tells the story of a Moorish Caliph about to appoint a Grand Vizier. “He invited the candidates to identify an object lying or floating in shallow water. All but one promptly said it to be an orange. One picked it up, and identified it as half an orange; he got the job.” We never see the whole of a solid object at any given moment; however, our brain completes an image on assumptions. You believe the globe in your room is a sphere, even though you never see all sides at once.

Friday, January, 25 2013 by

Weekly Optical Illusion: Blind Spot in the Optic Nerve

How many times did your driving instructor remind you to check your blind spot before switching lanes? Well, it turns out the old guy really knows what he’s talking about.

What is this nebulous blind spot? It turns out that the sheet of photoreceptors (little things that receive light) in our retina has a hole in it. Yes, you read that right: a hole. At one point, called the optic nerve head, neurons pass through the photoreceptor sheet to form the optic nerve, which transports the information the eye is receiving to the rest of the brain. It’s also the entry point for the blood vessels that supply the retina.
 

 
Obviously this nerve is pretty necessary, but there is one downside: due to the lack of photoreceptors at the optic nerve head, your brain doesn’t get any information from the area that’s missing. Now, as your probably know, brains are clever and they fill in this little spot with surrounding information so that we barely notice it. But, as this diagram will show you, it doesn’t disappear altogether.

Want proof? At a comfortable distance from your screen, cover your left eye and look at the crosshatch on the left. Now, slowly move your head towards the crosshatch and notice what happens to the black dot.
 

 
WHOA. Check that out! What is happening? At one point, the black dot disappears altogether. That is your blind spot! Just be glad it’s a black dot on a screen and not a car in the lane next to you.
 

Friday, October, 5 2012 by

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