Dyop® - Dynamic Optotype™

Helping the world see clearly, one person at a time




Personal Vision

Infant Vision

Color Screening

Professional Use


How it works







The New Metaphor of Vision - Can you really see clearly?


Your eyes function much like a digital electronic camera.  The photoreceptors in the back of your eye function much like the pixelized receptors in that electronic camera.  What you really see (if you can see clearly) are really pixels rather than lines or shapes.  The photoreceptors in your eyes send that pixelized image to your brain which uses it to bring the image into focus and give you your sense of vision.


A Dyop® (short for dynamic optotype) is a visual target (optotype) where the rotating/moving gap/segments provide the photoreceptors with a strobic stimulus which can be to measure visual acuity and refractions.  That strobic stimulus lets you sense your eyes pixel response to the images you are seeing. 


The personal version of the Dyop® test is at Dyop® Visual Clarity Test.  You can use this test to measure your visual clarity; however getting glasses or contact lenses requires a refraction by your eye doctor which CANNOT be done on a two-dimensional display such as a computer.  Measure your vision with the Dyop test, and if you can’t see clearly enough, GO SEE YOUR EYE DOCTOR.


Thousands of years ago our eyes developed primarily to spot predators and game as tools for our survival.  Visual clarity (acuity) was defined by the ability to see the nighttime gap between two of the smaller stars in the handle of the Big Dipper constellation.



Stellar Acuity

Static Letter-based Acuity

Strobic Stimulus Acuity


In 1862 acuity was re-defined as the ability to identify letters when reading became the dominant social skill.  However, European vision science used the convenience of black letters on a white background as the benchmark, although much of what we see is NOT in black and white, only a small portion of the earth’s population could read European letters, and letter-based testing was, and is, frequently inconsistent and imprecise.


Today’s visual acuity is measured by the comfort and ability to read text, especially text on an electronic display.  However, vision science has not kept up with the precision and demands of 21st century visual needs.


Much like the metaphor of the steam engine describing your heart as pumping blood through the body, or a computer describing how we think, the functioning of the eye is similar to an electronic camera.


When you look at a TV, or the display in front of you, you are actually seeing pixels rather than lines or shapes.  The pixels (very small dots of light) merge to give the impression of lines and shapes.  The pixels are so small, and pixel density so great that, unless you get VERY close to that display, you only see the lines and shapes rather than those pixels.  In fact, being aware of the pixels gets in the way of comprehending them as lines and shapes or words.



Light passes through the lens

to reach the retina

Retina Structure

Epithelium  =>  4 Neural Layers  =>  Photoreceptors


Photoreceptors as Pixels


Retina Color Perception

Wavelengths of light


Light   => 


 => Perception

Our biological eyes see the world as pixels rather than as lines and shapes.  What we see is recorded in the brain, but how we see starts as the pixelized stimulus of photoreceptors in the eye.  Those photoreceptors function as biochemical switches in response to light, primarily in red, green, and blue.  Those color responsive photoreceptors in the back of your eye function as pixels in your visual camera.  Clusters of about 100 photoreceptors have their pixel-like signal converted by the neurons in the retina into the impulse of one optic nerve fiber.  That optic nerve stimulus is then transmitted to the brain where the brain uses that stimulus to give us the perception/illusion of lines and shapes.


The visual clarity (acuity) of what we see is also regulated by those color-responsive photoreceptors in the back of the eye.  Light transmitted by the biological lens is separated into wavelengths of color.  That color separation effect typically has red focused slightly BEHIND the retina, green focused ON the retina, and blue focused in FRONT of the retina.  The disparity of the red/green/blue focal intensity is compared by the retina, and used by the brain, to autonomically transmit a stimulus to the muscles controlling the shape of the biological lens, and regulates the instantaneous adjustment of the focal length of the image (accommodation).


A Dyop® (short for dynamic optotype) is a calibrated visual target whose rotating/moving gap/segments create a strobic photoreceptor stimulus to measure visual acuity and refractions.  That strobic stimulus lets you sense the pixel response to the images you are seeing.


























1862 Snellen Vision Testing


21st Century Dyop® Vision Testing


When the Dyop® gap/segment stimulus size is too small, or the distance is too far away, you cannot detect the visual pixel response or rotation/motion of the Dyop® gap/segments.  That minimum Dyop® diameter and gap/segment stimulus where you CAN detect the Dyop® motion is the acuity endpoint.


The 1862 “standard” for acuity uses a letter-based test to detect perception of the differences between static letters such as “E” and “C.”  However, the use of static letters is as much a test of cognition as it is acuity.  Static letter tests, rather than enhancing visual acuity, increase visual stress, increase decision fatigue, and create a less precise visual acuity measurement.


The Dyop® motion detection process increases accommodative rest, takes the guesswork and visual stress out of vision testing, and potentially increases the efficiency of the visual testing process.  Dyop® vision tests are more accurate than static image tests, more precise, more consistent, potentially faster to use, and do not require the ability to read, let alone the ability to read English.


Calibrated Dyop® tests are intended as a global replacement for Snellen, Sloan, and Landolt optotypes.



“Any sufficiently advanced technology is indistinguishable from magic.”
- Arthur C. Clarke’s Third Law


As a culture we are only as good as our memory.  As a species we are only as good as our vision.


Just as the hand, held before the eye, can hide the tallest mountain, so the routine of everyday life can keep us from seeing the vast radiance and the secret wonders that fill the earth.

-          Chasidic, 18th Century


The Dyop® (Dynamic Optotype™) tests and concept are covered under U.S. Patent US 8,083,353

and International Published Patent WO 2011/022428.

For further information contact: Allan Hytowitz at Allan@Dyop.org

5035 Morton Ferry Circle, Alpharetta, GA, 30022   /   678-893-0580

Copyright©2016 Dyop® Vision Associates.  All Rights Reserved