Dyop® - Dynamic Optotype™

Helping the world see clearly, one person at a time




Personal Vision

Infant Vision

Color Screening

Professional Use


How it works

Using the Test

Visual Impairment

How it works

Using the Test




We see the world as pixels from a TV, rather than as lines and shapes.


We think in metaphors.  We use the metaphor of a computer to describe how we think.  We use the metaphor of a steam engine to describe our heart pumping blood through our body.


The metaphor of a digital TV camera or electronic display can be used to describe how we see. 


When you look at a TV, or this electronic display, you are really seeing pixels – small dots of light that merge together to give you the impression that you are seeing lines and shapes.  The pixels are so small, and the pixel density so great, that unless you get VERY close to the display you only see the lines and shapes rather than those pixels.


The color sensitive photoreceptors in the back of your eye function as pixels in your visual camera.  They are so small, and with such a high pixel density that it becomes virtually impossible to sense them as pixels and realize that what you see is anything other than lines and shapes and points.  Clusters of about 100 pixel-like photoreceptors have their signal converted by the neurons in the retina into the impulse of one optic nerve fiber, which is then transmitted to the brain.  The brain uses that optic nerve stimulus to give us the illusion of lines and shapes.



Light passes through the lens to reach the retina


Retina Structure

Epithelium  =>  4 Neural Ganglia Layers  =>  Photoreceptors


   Retina Color Perception

Wavelengths of light





















Light transmitted by the biological lens is also separated into wavelengths of color.  That 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 transmitted to the muscles controlling the shape of the biological lens, which in-turn regulates the instantaneous adjustment of the focal length of the lens (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.


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


Current visual “standards” for acuity (how clearly we see) use an 1862 letter-based test to detect our perception of the differences between static letters such as “E” and “C.” 

























1862 Snellen Vision Testing

21st Century Dyop® Vision Testing


However, the use of letters is as much a test of cognition as it is acuity.  The use of letters is culturally and literacy biased, is significantly imprecise and inconsistent, and doesn’t sufficiently meet the high precision needs of 21st century technology in measuring visual 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


People who are able to consistently see more clearly are more productive and able to successfully participate and benefit from 21st century technology significant increases.


 “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.




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