Dyop® - Dynamic Optotype™

Helping the world see clearly, one person at a time




Personal Vision

Infant Vision

Color Screening

Professional Use


How it works







Vision as the Ultimate Illusion. 

Introducing the "revolutionary" Dyop® method of measuring vision





Dyop Vision Webpage







Dyop Video





   Dyop Strobic Stimulus



Vision is the Ultimate Illusion.  We think we are seeing lines or shapes or letters as you are reading, this likely on a computerized display.  What you are really seeing as letters, lines, and shapes are pixels of light generated by the phosphors within the surface of the computer screen.

Those electronic phosphor pixels are perceived by the photoreceptors of your eye functioning as biological pixel which combine their response (primarily in colors of
red, green, and blue) into giving you the illusion of vision. 


Our bodies are biological machines, and our vision functions best as an autonomic process.  Our eyes developed primarily as sensors for detecting motion, distance, and colors so that humans could better detect predators and game, and eat rather than be eaten.   To see most efficiently we have to be totally unaware of the mechanics of that process. 


Dyop® (short for dynamic optotype) is spinning segmented ring visual target.  Dyop gap and segment constant rate of spin creates a binary strobic stimulus of the photoreceptors of the eyes.  That gap/segment strobic stimulus can be used to measure acuity (visual clarity) and determine refractions. The smallest diameter Dyop ring, detected as spinning, creates an acuity and refraction endpoint which not only allows you to measure vision in black and white, but to also precisely measure vision in color.


When the spinning gap/segment area of a Dyop gets too small, that binary visual stimulus is too small for the photoreceptors to detect that motion.  The smallest Dyop stimulus area detected as spinning (an area of about 20 photoreceptors) creates a visual clarity stimulus threshold used to measure vision.  That threshold, as used by doctors to measure visual acuity and refractions, is significantly more precise, consistent, and efficient than staring at letters.



21st Century Vision Can No Longer Rely on 1862 Technology

Our eyes developed primarily as vision sensors to detect motion as well as distance and color.  That detection allows humans to detect predators and game, and to eat rather than to be eaten.  Vision “standards” from 1862 are based upon the cultural ability to detect the size and difference between static letters such as “E” and “C.” As a result it tends to mistake cognition for acuity, and improperly and imprecisely “measure” vision.





We see in six variables – height, width, viewing distance, color and intensity, motion (or stimulus time), and binocular fusion, and NOT just by measuring the image height and distance.  “Classical” 1862 based vision tests measure vision in only three variables – height, distance, and binocular fusion.  “Classical” tests are inherently imprecise because they also use cognition of cultural shapes as the benchmark rather than the physiological response of the eye.


How the Dyop test works


The bioelectrical responses of the photoreceptors of the eye function much as the pixels in a computerized video camera.  Your brain uses the response of about 100 photoreceptors for every optic nerve going to the brain to create vision and bring that image into focus.  The retina neural ganglia layers “process” those photoreceptor responses in clusters of about 20 photoreceptors as a biological circuit board with the emphasis on patterns of motion and proximity.  The photoreceptors not only allow you to see in color (primarily red, green, and blue for most people), but the refresh rate of the photoreceptors and the saccade process allow you to track changes in the location of those images.  The comparative focal depth of the red, green, and blue stimulus of those images regulates the shape of the lens and the focal clarity.


However, we normally aren’t aware of that photoreceptor strobic stimulus because it would interfere with being able to see the lines and shapes as transmitted to the brain.  We literally would "see the trees rather than the forest."  The loss of cognition would be the same as if you got close enough to see the pixels on your monitor.  You totally lose the ability to see the shapes and understand the words.  It is also why fixating on a shape will also literally have that shape seem to disappear as the photoreceptors lose their refresh ability to bio-electronically respond.




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


Faster and more accurate visual acuity testing


When using the 1862 Snellen test and other static image charts which derived from it, those target letters get increasingly blurry as they get smaller.  Cognition of European-type letters based letters become a guessing game for both the doctor and patient and measures conceptual processing by the patient as much as it does visual clarity. 


For Dyop testing, when the Dyop diameter (angular width) and the gap/segments gets sufficiently smaller, the binary strobic stimulus on the photoreceptors is no longer sufficiently large enough for the spinning of the gap/segments to be detected by the photoreceptors. The smallest Dyop diameter (arc width) detected as spinning creates a visual clarity threshold, which is used by doctors to measure visual acuity and the refraction endpoint, and is more precise, consistent, and efficient than staring at letters. The direction of spinning is irrelevant.  That process of spinning detection also lets the Dyop test be used for individuals who “can’t read,” infants and young children, and individuals with letter-processing problems such as dyslexia.


The History of Vision Measurement


Hundreds of thousands of years ago our eyes developed as survival tools to spot predators and game.  Thousands of years ago, 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

Dyop Strobic Stimulus Acuity


In 1862 Dutch ophthalmologist Dr. Herman Snellen defined visual acuity as the ability to identify letters, since reading had become a dominant social skill.  European vision science used the convenience of black letters on a white background as the acuity benchmark, although much of what we see is NOT in black and white.  Also, only a small portion of the earth’s population could read those European letters, and that Snellen letter-based response was, and is, frequently inconsistent and imprecise.


























1862 Snellen Vision Testing


21st Century Dyop® Vision Testing


The strobic Dyop stimulus lets you sense the pixel response to the images you are seeing.


However, twenty first century technology is letter-based technology.  Today’s visual acuity is primarily measured by the clarity and ability to read text on an electronic display.  Unfortunately, vision science has not kept up with the precision and demands of those 21st century visual needs.



The added precision and consistency of the Dyop® tests are intended as a global replacement for static letter-based tests such as Snellen, Sloan, and Landolt optotypes.


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


Dyop® tests are for vision screening purposes only and are NOT a substitute for an examination by a licensed vision care professional. 



“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

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