Dyop® - Dynamic Optotype™

        Helping the world see clearly, one person at a time




Personal Vision Test

Children’s Vision Test

Color Screening and Dyslexia Screening

Professional Test


How it works


Visual Impairment






It Spins.  You See It.


Introducing the "Revolutionary" Dyop® Test


The 21st Century Test for Precisely Measuring Vision

Which Takes the Guesswork out of Vision


Vision is a dynamic process which enables us to eat rather than be eaten.  The vibratory motion of the visual saccades is inherent in all animals and refreshes the response of the photoreceptors in the back of the retina.  That refresh allows the images we see to be dynamic and autonomic as the neurons on the retina inner surface act as the equivalent of a biological circuit board. The constant motion of the saccades allows the blue, green, and red photoreceptors to use the chromatic triangulation of their focal depths to regulate acuity. The result is that vision tests using static visual targets tend to be unnecessarily imprecise and inconsistent, and may actually be making people blinder. 


A Dyop® (short for dynamic optotype where “optotype” is the technical term for a visual target) is a spinning segmented ring with contrasting (typically Black/White) segments and gaps which provide a strobic stimulus to the photoreceptors as they spin. The Dyop angular width diameter is used as an indicator and visual target for measuring acuity and refractions, and uses Resonance Acuity to match the saccade refresh rate of the photoreceptors.   The smallest Dyop angular width diameter where the direction of spin can be detected is the visual acuity and refraction endpoint.  At a Dyop sub-acuity diameter, the direction of spin cannot be detected. The motion of the saccades results in the strobic Dyop segment/gap motion Resonating with the saccades refresh rate and functioning much as a visual equivalent of an audio tuning fork.  That strobic Resonance Acuity results in Dyop vision testing being three times as precise, with one-sixth the variance, and up to three times the efficiency of Snellen and other letter-based vision testing.




1862 Snellen Vision Testing

                21st Century Dyop® Vision Testing





























Culturally dependent Snellen Letters

             Typical Dyop Acuity Increments - for use on a 21 inch monitor at 6 feet (2 meters)


Unlike letters, which are culturally dependent on Recognition Acuity, a Dyop uses Resonance Acuity based on the physiological refresh response of the photoreceptors of the eye.  As a Dyop ring gets smaller, or you move further away from your computer screen, you should no longer be able to detect a smaller Dyop ring as it is spinning.  The smallest diameter Dyop ring whose gaps/segments are detected as spinning serves to precisely benchmark acuity (visual clarity), and can be used to determine acuity and refractions regardless of culture or literacy skills.


Resonance Acuity and the photoreceptor refresh response are essential for survival and give your eyes a preference for detecting motion.  As you fixate on the Plus (+) in the circle image below you will likely see a moving Green circle which appears as the Pink circles seem to rotate around that Plus.  The moving Green circle appears because of the strobic photoreceptor refresh rate, the depletion of the Red photoreceptors, and their (depleted) inability to respond to the color Red in the Gray background. 



A strobic stimulus lets you sense your pixelized response to the images you are seeing.


The Lilac Chaser Illusion



Fixate on the + in the center of the spinning pink dots and notice that the moving gray area becomes a green dot due to photoreceptor depletion.



The Lilac Chaser Illusion





Dyop visual testing has greater precision and less variance than static visual targets







Dyop Components


Item 1 – the visual angular movement/velocity for the strobic contrast response (40 RPM)

Item 2 – the moving segmented 0.54 arc minute squared minimum visual area (MAR) for dynamically stimulating a cluster of 20 retina photoreceptors

Item 3 – retinal cell clusters

Item 4 – examples of static historic optotypes

Item 5 – the static 1.0 arc minute squared minimum area (MAR) of Resolution/Recognition for a cluster of 40 retina photoreceptors with a historic optotype



Dyop Professional Test


Your eyes function similar to the pixels receptors in a computerized video camera.  As you read these words you have the illusion that you are seeing lines and shapes and letters.  What you are actually seeing are pixels of light generated by electronic phosphors within the surface of your computer screen.  However, those electronic pixels are perceived by the photoreceptors of the retina in the back of your eye.  Those photoreceptors in your retina respond to light as biological pixels.  Those biological photoreceptor pixels combine their response (primarily to the colors blue, green, and red) into giving you the perception of vision. 


Color Screening and Dyslexia Screening


The eye’s photoreceptors not only allow you to see in color, but the refresh rate of the photoreceptors combines with the strobic saccade process to create a matrix response to color-perception which allows the photoreceptors to track changes in the location of those images.  The saccade process functions much as does the scanning lines of the pixels on your computer monitor to keep the image from burning into the screen.  The response of about 100 photoreceptors combines to create the stimulus for each optic nerve fiber going to the brain which creates vision and brings that image into focus.  However, the neural ganglia layer of the retina “process” those photoreceptor responses in clusters of about 20 photoreceptors much as a biological circuit board with the emphasis on patterns of motion and proximity.  The comparative focal depth of the colors blue, green, and red of the images also regulates the shape of the biological lens and adjusts focal clarity.






Light passes through the lens to reach the retina and creates chromatic triangulation

Light => => Perception

Retina Structure -  4 Neural Layers






Photoreceptors as Pixels

Retina Color Perception

Wavelengths of light




The History of Vision Measurement


Thousands of years ago, visual clarity (acuity) used Resolution Acuity as defined by the ability to see the nighttime gap between two of the smaller stars in the handle of the Big Dipper constellation.


Resolution Acuity

Recognition Acuity

Resonance Acuity


In 1862 Dutch Ophthalmologist Herman Snellen used the Recognition Acuity ability to identify (European) letters as a benchmark for visual acuity.  By then, reading had become a dominant economic and social skill in Europe.  Snellen used the convenience and cultural bias of black letters on a white background as his benchmark, although most of what we see is NOT in black and white, and other cultures use pictographs rather than letter-based words.  The Dyop Resonance Acuity is three times as precise, with one-sixth the variance, and up to three times the efficiency of Snellen and other letter-based vision testing.












In an era where SmartPhones and computers are ubiquitous,

the inherent errors of the Snellen test are no longer acceptable. 


21st century vision needs can no longer rely on 1862 technology


Current global vision “standards” are based upon “Recognition Acuity” and the 1862 cultural skill of being able to detect the identity and size differences between static letters, such as “E” and “C.” 


As a result, that 1862 Snellen method is dependent upon cognition and culture, and improperly and imprecisely measures vision. 


The Dyop uses the physiology of the eye and “Resonance Acuity” to be potentially more precisely (3x), more consistently (6x), and more efficiently (4x) measure vision.









The personal use of the Dyop test is intended to only measure visual clarity.  A PRESCRIPTION for glasses or contact lenses requires vision testing and a refraction performed by an eye doctor because it CANNOT be done on a two-dimensional display such as a computer. 


You can measure your vision with the Dyop test using the Dyop Personal Acuity Test. 


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   /   404-281-7798

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