Even More Incredible Illusions

Published on
January 5, 2022

Optical illusions are one of the best reminders that vision is a system made up of more than just the eyes. It’s the brain that organizes the input it receives and determines what we see. Optical illusions take advantage of how our visual system works to create the mind-bending visuals we’ve all run into at some point.

Here is a look into another couple optical illusions

The Chubb Illusion


This illusion was discovered by Charles Chubb and his colleagues Sperling and Solomon in the late 1980s, during experiments with perceived contrast. In the image here, the gray circle on the simple gray background and the gray circle on the black and white, textured background, are identical, despite appearing to us as different shades of gray.

This can be explained through the concept of imperfect transmittance, which is where the brain has to see through ambiguity in order to perceive an object. (More practical examples are when we look at something from a distance or through fog.) When there is minimal light around the object, the brain attempts to determine its color and contrast by making an educated guess based on the background around the object.

As is the case here, that interpretation isn’t always correct.

The Poggendorff Illusion


Take a look at the image here. Does the black line look like it lines up with the blue line? The truth is, the black line lines up with the red one, as the second image reveals.

This illusion is named for Johann Poggendorff, the German physicist who first detailed this illusion in 1860. While it is clearly a demonstration of how our minds perceive depth and geometric shapes, there is no universally accepted explanation for it.

The most widely accepted theory, however, is that in this illusion our brain is trying to interpret the two dimensional image with three dimensional properties, and in the process it’s distorting the depth between the lines.

Shepard’s Table


The Shepard’s Table illusion was first created by American psychologist Robert Shepard in a book he published in 1990, and provides yet more evidence that our visual system is primarily influenced by our lived experiences with the world around us, to the point where it can mess with our view of reality.

In the image here, the two tables look to be of very different size and shape. In actuality, they are exactly the same! This animated illustration can prove it to you.

This is another illusion caused by the fact that our brain tries to interpret 2D images in the same way it interprets 3D ones. It perceives different sizes because of perspective foreshortening, which means that the closer an object is, the larger it appears on the retina.

Optical illusions are endlessly fascinating, both because they’re simply interesting to look at, and because they can teach us a lot about the visual system. Go explore some more optical illusions!


Such a nice optician. My grandson is only 4 and needs glasses. We were so sad, but he explained the issues, and we will follow up as he suggested.

Anna P.

I had such a good experience with the clinic. Very friendly staff and doctor, did not have to wait for long to be called, and was treated respectfully. Thanks, American Family.

June S.

Dr. Zurcher has gone above and beyond what any other eye doctor has ever done to figure out what is going on with my eyes. Very happy with American Family Vision.

Christine R.

Family Vision Clinic changed our lives! My daughter was frequently car sick, and she was getting headaches every day, often painful enough that they brought her to tears. We saw a string of doctors and therapists, but we made no progress. Finally, we found Dr. Levi Zurcher and his eye therapist Rain. After ten weeks of eye therapy my daughter no longer gets headaches, and she no longer gets car sick. Daily tears are a thing of the past. I really can’t say enough about this clinic. It was fascinating to watch Dr. Zurcher work. For the first time, someone who knew what they were doing was intently studying my daughter, really trying to figure out all of her eye issues, and his therapist Rain is one of the most patient and lovely people that I’ve ever had the good fortune to meet. We’re finished with eye therapy—yay!—and I have switched to American Family Vision Clinic for all of my family’s other eye health needs.

Lars Wulff

Very professional, yet kind and helpful. They do what they can to make the appointment comfortable. I was running a bit late, I made sure ti call. They were able to switch me with a patient who was already there, they treated me with respect, and helped my son have confidence by getting him the eye care he needed that day. Thank you so much! Would recommend to anyone. It's a blessing that they care enough to work with people who have all different types of insurance from work to state coverage.

Justin E.

The staff is friendly. The Doc is very knowledgeable. The office is family friendly and everyone is so patient with the little ones.

Amy Fagerness
1 2 3



Discover effective treatment options for diabetic retinopathy; consult our eye care professionals to protect your vision and overall well-being

Treating diabetic retinopathy Treating diabetic retinopathy is a critical aspect of preserving vision and maintaining the overall quality of life […]

Read More
Carrots for eyes

Are Carrots Good for Your Eyes?

As an optometrist at American Family Vision Clinic in Olympia, one of the most common questions Dr. Levi Zurcher often […]

Read More

Understanding Foggy vision

Is foggy vision troubling you? Let our experienced optometrist restore your sight – book an appointment today and see the […]

Read More
see all blogs

Contact Us To Amplify Your EyeCare

American Family Vision Clinic Logo

Working Hours




400 Yauger Way SW. Bldg 1, Ste A Olympia, WA 98502
(360) 459-1097
Website Accessibility Policy
Safety protocols page
privacy policy
For Patients
Call Us
eyefile-adduserphone-handsetcalendar-fullarrow-uparrow-right linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram